public List <Customer> GetCustomerByPhoneNumber(string locationCode, string phoneNumber, string phoneExtension)
        {
            List <Customer> customers = new List <Customer>();

            DataTable customerDetails = CustomerDataAccess.GetCustomerByPhoneNumber(locationCode, phoneNumber, phoneExtension);

            customers.AddRange(EntityHelper.ConvertDataTable <Customer>(customerDetails));

            return(customers);
        }