Substring match in elasticsearch with conditions

I am trying to perform an Elasticsearch query, where I am supposed to get all restaurants which contain the substring 'pizz' in the restaurant name but do not contain neither 'pizza' nor 'pizzeria'.

The query I wrote for this purpose is this:

GET my_index/_search
{
  "query": {
    "bool": {
      "must": [
        {
          "wildcard": {
            "RestaurantName": {
              "value": "*pizz*"
            }
          }
        }
      ],
      "must_not": [
        {
          "match": {
            "RestaurantName": "pizza"
          }
        },
        {
          "match": {
            "RestaurantName": "pizzeria"
          }
        }
      ]
    }
  }
}

This query matches fields like Instapizza which is wrong. It should match anything combined or uppercase cases like: Fozzie's Pizzaiolo, PizzaVito, Pizzalicious. How can I fix the query to lose the match for unwanted fields? Any help with this would be really great.

When you index 'RestaurantName' as a text field, the "Standard" analyzer includes the lowercase filter, "lowercase" token filter makes fields case-insensitive, which means all tokens in lucene are lowercase.

first, you should add an extra keyword type to RestaurantName field.

{
    "mappings": {
        "properties": {
            "RestaurantName": {
                "type": "text",
                "fields": {
                    "keyword": {
                        "type": "keyword",
                        "ignore_above": 256
                    }
                }
            }
        }
    }
}

search with wildcard,

{
    "query": {
        "bool": {
            "must": [
                {
                    "wildcard": {
                        "RestaurantName.keyword": {
                            "value": "*Pizz*"
                        }
                    }
                }
            ],
            "must_not": [
                {
                    "match": {
                        "RestaurantName": "pizza"
                    }
                },
                {
                    "match": {
                        "RestaurantName": "pizzeria"
                    }
                }
            ]
        }
    }
}

the result is,

{
    "took": 8,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 3,
            "relation": "eq"
        },
        "max_score": 1.0,
        "hits": [
            {
                "_index": "pizza",
                "_type": "_doc",
                "_id": "1L6ob4cB6Rdc8HbDY8vi",
                "_score": 1.0,
                "_source": {
                    "RestaurantName": "Fozzie's Pizzaiolo"
                }
            },
            {
                "_index": "pizza",
                "_type": "_doc",
                "_id": "1b6ob4cB6Rdc8HbDg8tA",
                "_score": 1.0,
                "_source": {
                    "RestaurantName": "PizzaVito"
                }
            },
            {
                "_index": "pizza",
                "_type": "_doc",
                "_id": "1r6ob4cB6Rdc8HbDmMuJ",
                "_score": 1.0,
                "_source": {
                    "RestaurantName": "Pizzalicious"
                }
            }
        ]
    }
}