Netsuite Suitetalk: How to get all the customers whose account balance has changed

@operator

Customer lastModifiedDate is not updated if you create cash sale/invoice of a particular customer in Netsuite. customer balance is changed but customer lastModifiedDate is not changing. how can I get all those customers their balance is updated as per lastModifiedDate.

Please have a look at the code below.

 CustomerSearch customerSearch = new CustomerSearch();              CustomerSearchBasic customerBasic = new CustomerSearchBasic();    customerBasic.lastModifiedDate = new SearchDateField()  {         @operator = SearchDateFieldOperator.onOrAfter,         operatorSpecified = true,         searchValue = new DateTime(2018, 10, 20, 13, 50, 00, DateTimeKind.Utc),         searchValueSpecified = true,  };    customerSearch.basic = customerBasic;    SearchResult result = ACGApplication.Client.Service.search(customerSearch);  var customerList = result.recordList.Cast<com.netsuite.webservices.Customer>();