public async Task <List <Contact> > DeleteContactAsync(List <Contact> listContact) { List <Contact> result = new List <Contact>(); checkServiceCommunication(); List <Contact> gateWayResultList = await _gateWayClient.DeleteContactAsync(listContact); if (gateWayResultList.Count == 0) { foreach (Contact contact in listContact) { int returnResult = _dataSet.DeleteContact(contact.ID); if (returnResult > 0) { result.Add(contact); } } } return(result); }