The following error messages can be generated by get_acct_contacts_m.
1001: unexpected error
1004: authentication error
Associated Inputs: auth_key, client_id, client_no
1009: account does not exist, Account not found: AriaNo (acct_no), Account not found: Userid (userid), or
Account not found: ClientId (client_acct_id)
Associated Inputs: acct_no, account_no, client_acct_id, user_id, userid, parent_acct_no
26010: Invalid billing group number
Associated Inputs: billing_group_no
26012: Invalid client-defined billing group ID.
Associated Inputs: client_billing_group_id