Unable to mock accountStatus with Mockito

From below piece of code I am not able to mock checkAccountStatus and its coming as null. What changes do I need to do to resolve this issue?

Class

public AccessIDSearchResponse searchAccessID(AccessIDSearchRequest accessIDRequest) {
		String[] productTypes = accessIDRequest.getProductTypes();
				AccountResponse actResponse = checkAccountStatus(accessIDRequest);
				System.out.println("Response is---->"+JsonService.getJsonFromObject(actResponse));
				if (accessIDRequest.getSearchtype().equalsIgnoreCase("accountId") && !Utility.isEmpty(actResponse)
						&& !"FREEVIEW".equalsIgnoreCase(actResponse.getAccountStatus())) {
					errorHandler.error(ErrorMessages.EPO_EXISTINGTV_ERR_07, ErrorMessages.ACCESS_ID_NOT_FOUND);
			}
}

public AccountResponse checkAccountStatus(AccessIDSearchRequest request) {
			AccessIDSearchResponse response = new AccessIDSearchResponse();
			SearchAccessIdContent content = new SearchAccessIdContent();
			DTVNAccountDetails accountDetails = new DTVNAccountDetails();
			accountDetails.setAccountNumber(request.getSearchvalue());
			List<DTVNAccountDetails> list = new ArrayList<>();
			list.add(accountDetails);
			content.setDtvAccountList(list);
			response.setContent(content);
			return helper.getAccountStatus(response);
	}

Helper

public AccountResponse getAccountStatus(AccessIDSearchResponse accessIDResponse) {
		AccountResponse accountResponse = null;
			AccountRequest request = new AccountRequest();
			Account account = new Account();
			account.setCustomerID(accessIDResponse.getContent().getDtvAccountList().get(0).getAccountNumber());
			request.setAccount(account);
			String response = dtvnClients.callandGetDtvnStatus(request);
			System.out.println("Response is--->"+response);
			if (!Utility.isEmpty(response)) {
				accountResponse = JqUtil.runJqQueryAndGetString(".content.accountResponse", response,
						AccountResponse.class);
				if (!Utility.isEmpty(accountResponse) && accountResponse.isSubscribable()
						&& !Utility.isEmpty(accountResponse.getAccountStatus())
						&& accountResponse.getAccountStatus().equalsIgnoreCase("FREEVIEW")) {
					return accountResponse;
				} 
			}
		return accountResponse;
	}

Test Class

@Test(expected = ServiceException.class)
	public void test_searchAccessID_3_sample() throws Exception {
		AccessIDSearchRequest request = new AccessIDSearchRequest();
		CommonData commonData = new CommonData();
		commonData.setAppName("IDSE");
		commonData.setLoginId("qay_slid_sr1281");
		request.setCommonData(commonData);
		request.setSearchtype("accountId");
		request.setSearchvalue("qay_slid_sr1281");
		request.setMode("abc");

		SearchAccessIdContent content = new SearchAccessIdContent();
		AccountResponse accountResponse = new AccountResponse();
		accountResponse.setAccountStatus("Sucess");
		accountResponse.setSubscribable(true);

		Mockito.when(helper.getAccountStatus(accessIDResponse)).thenReturn(accountResponse);
		Mockito.when(service.checkAccountStatus(request)).thenReturn(accountResponse);

		service.searchAccessID(header, request);
	}

Your mocks are not properly configured.

When you call

 service.searchAccessID(header, request);

it was make the underlying call

checkAccountStatus(request);

(which is correctly mocked and returns accountResponse), but this one does instanciate its result object, so your first mock will never be triggered.

Updating your first mock to something more permissive will probably fix your problem

Mockito.when(helper.getAccountStatus(any(AccessIDSearchResponse.class))).thenReturn(accountResponse);

To be honest, your code is hardly testable because you instanciate too many objects everywhere. Going for mocks here will be a pain in the future when you refactor something. If I were you I would rewrite this piece of code using a TDD approach and favorizing more testable patterns.