How to populate data that don't match specific criteria in table?

I have 2 tabs, 1 Summary tab and the other 1 is Data tab. The summary tab contains a table with specific customer numbers(as shown in the summary table below).

I'm trying to achieve the same set of data and columns that are listed in the summary table but for the rest of the customer numbers that do not exist in the summary table and insert them in a listbox.

can anyone help me please with that?

Thank you!

My Summary Table:

My Data source

 Option Explicit
                
                Sub test()
                Dim conn, rs As Object, sq As String, Accounts As String
                
                Set conn = CreateObject("ADODB.Connection")
                  With conn
                    .Provider = "Microsoft.ACE.OLEDB.12.0"
                    .ConnectionString = "Data Source=" & 
                      ThisWorkbook.FullName & ";" & _
                    "Extended Properties=""Excel 12.0 
                           Xml;HDR=Yes;IMEX=1"";"
                    .Open
                      End With
                       
                           sq = "SELECT T1.[Customer Number],T1. 
                                [Customer Name],T1.[Aged Debt] " & _      
                "COUNT(T1.[Invoice Number]) as [count of Invoices] " & _ 
                                "sum(T1.[Value]) as [values] " & _
                                "FROM[Data$] T1 " & _
    "WHERE T1.[Customer Number] Not In (" & Getcust(Accounts) & ") " & _
     "GROUP BY T1.[Customer Number],T1.[Customer Name],T1.[Aged Debt]"
                                        
             Set rs = conn.Execute(sq)
                                           
              If Not rs.EOF Then
               With Me.listbox1
                .Value = ""
               .Column = rs.GetRows
              .ColumnCount = rs.Fields.Count
              .ColumnHeads = False
             .ColumnWidths = "90,90,50,50,180"
                                        End With
                                       End If
                                       
                         rs.Close
                         conn.Close
                       Set rs = npthing
                       Set conn = Nothing
                       
                       
                       End Sub
                
   

     Public Function Getcust(Accounts As String) As String
       Dim dU1 As Object, cU1 As Variant, iU1 As Long, i As Integer
                        Set dU1 = CreateObject("Scripting.Dictionary")
               cU1 = Sheets("Summary").ListObjects(1).ListColumns("Customer 
                      Number").DataBodyRange
                        For iU1 = 1 To UBound(cU1, 1)
                            dU1(cU1(iU1, 1)) = 1
                        Next iU1
                              Accounts = "'"
                        For i = 0 To dU1.Count - 1
                           Accounts = Accounts & dU1.Keys()(i) & "','"
                        Next
                          Accounts = Left(Accounts, Len(Accounts) - 5)
                          Getcust = Accounts
                          
    End Function

Write two Connection Only Power queries to read your Summary Data and your Datasource
Then Merge those queries using a LeftAnti join to get only the rows in data source that do not exist in the summary.
You can then use Transform, Group By to get the details you need for your summary e.g.

let
    Source = Table.NestedJoin(DataSource, {"Customer Number"}, Summary, {"ustomer Number"}, "Summary", JoinKind.LeftAnti),
    #"Grouped Rows" = Table.Group(Source, {"Customer Number", "Customer Name", "aged debt"}, {{"Count of invoices", each Table.RowCount(_), Int64.Type}, {"Value", each List.Sum([Value]), type nullable number}})
in
    #"Grouped Rows"

Please, use the next standard way. You must set your lisObjects (tables) from the place (worksheets) where they really exist. The active sheet must contain an ActiveX listbox, named "ListBox1":

Sub LoadListBoxWithNotExistingCustomNo()
   Dim tbl1 As ListObject, tbl2 As ListObject, arrT1, arrT2, arrUnique, mtch, arrIt, arFin
   Dim i As Long, j As Long, dict As New Scripting.Dictionary
   Dim listB As msforms.listbox
   
   'use here the real sheets where the two involved tables exist:
   Set tbl1 = ActiveSheet.ListObjects("T1.") 'the first table Object
   Set tbl2 = ActiveSheet.ListObjects("T2.") 'the second table Object
   
   arrT1 = tbl1.DataBodyRange.Value2 'place their contents in an array for faster processing
   arrT2 = tbl2.DataBodyRange.Value2
   
   For i = 1 To UBound(arrT1)
        dict(arrT1(i, 1)) = vbNullString 'extract the unique Customers numbers
   Next i
   arrUnique = dict.keys 'place the dictionary keys in an array
   dict.RemoveAll 'empty the dictionary to reuse it...
   
   'load in the dictionary the necessary data:
   For i = 1 To UBound(arrT2)
        mtch = Application.match(arrT2(i, 1), arrUnique, True)
        If Not IsNumeric(mtch) Then
            If Not dict.Exists(arrT2(i, 1) & "|" & arrT2(i, 6)) Then
                dict.Add arrT2(i, 1) & "|" & arrT2(i, 6), Array(1, arrT2(i, 2), arrT2(i, 7))
            Else
                arrIt = dict(arrT2(i, 1) & "|" & arrT2(i, 6))   'place the item in an array
                arrIt(0) = arrIt(0) + 1 'count the number of occurrences
                arrIt(2) = arrIt(2) + arrT2(i, 7) 'add the values
                dict(arrT2(i, 1) & "|" & arrT2(i, 6)) = arrIt 'drop back the updatred ltem array
            End If
        End If
   Next i
   
   'load the final array:
   ReDim arFin(1 To dict.count, 1 To 5)
   For i = 1 To dict.count
        arFin(i, 1) = Split(dict.keys()(i - 1), "|")(0) 'the customer Number
        arFin(i, 3) = Split(dict.keys()(i - 1), "|")(1)  'the aged delay
        arFin(i, 2) = dict.Items(i - 1)(1) 'Customer name
        arFin(i, 4) = dict.Items(i - 1)(0)  'Count of Invoices
        arFin(i, 5) = dict.Items(i - 1)(2)  'Count of Invoices
   Next i
   
   Set listB = ActiveSheet.OLEObjects("ListBox1").Object: 'set the ActiveX list box
   With listB
        .ColumnCount = UBound(arFin, 2) 'set the list box number of columns
        .List = arFin 'drop the array content in the list box
   End With

End Sub

Edited for using Worksheets instead of Tables:

Sub LoadListBoxWithNotExistingCustomNoInSheets()
   Dim ws1 As Worksheet, ws2 As Worksheet, arrT1, arrT2, arrUnique, mtch, arrIt, arFin
   Dim i As Long, j As Long, dict As Object
   Dim listB As msforms.listbox
   
   Set ws1 = ActiveSheet 'use here the sheet you need ("My Summary Table")
   Set ws2 = ActiveSheet 'the same. I am using the same sheet because I had two tables, now transformed in ranges ("My Data source")...
   
   Dim lastR As Long
   lastR = ws1.Range("A" & ws1.rows.count).End(xlUp).row 'last row for the former first table
   arrT1 = ws1.Range("A2:E" & lastR).Value2  'place their contents in an array for faster processing
   
   lastR = ws2.Range("H" & ws2.rows.count).End(xlUp).row 'last row for the former second table (take care of the first range column TO BE USED)
   arrT2 = ws1.Range("H2:N" & lastR).Value2 'you should use your range in terms of necessary columns from second sheet ("My Data source")...

   Set dict = CreateObject("Scripting.Dictionary")

  '................
  'the existing code remains unchanged...
End Sub

If something not clear enough related to the code comments, do not hesitate to ask for clarifications.

Edit 2

Microsoft Scripting Runtime reference can be added running the next piece of code:

Sub addScrRunTimeRef()
  'Add a reference to 'Microsoft Scripting Runtime':
  'In case of error ('Programmatic access to Visual Basic Project not trusted'):
  'Options->Trust Center->Trust Center Settings->Macro Settings->Developer Macro Settings->
  '         check "Trust access to the VBA project object model"
  Application.vbE.ActiveVBProject.References.AddFromFile "C:\Windows\SysWOW64\scrrun.dll"
End Sub