XML

  <function name="rpcf_cancel_payment_for_account" id="0x3111">
    <input>
      <integer name="pay_t_id" />
      <string name="com_for_user" />
      <string name="com_for_admin" />
    </input>
    <output/>
  </function>

PHP

Не проверено, только набросок! 

	function rpcf_cancel_payment_for_account($pay_t_id,$com_for_user='',$com_for_admin='') { //0x3111
		if (!$this->connection->urfa_call(0x3111)) { 
			print "Error calling function ". __FUNCTION__ ."\n";
			return FALSE;
		}
		$packet = $this->connection->getPacket();
		$packet->DataSetInt($pay_t_id);
		$packet->DataSetString($com_for_user);
		$packet->DataSetString($com_for_admin);
		$this->connection->urfa_send_param($packet);
		$this->connection->urfa_get_data(); 
	}