Refund payments using Authorize.net AIM API - php

Question

I am trying to find a way to refund payments using Authorize.net's AIM API. I found sample code located here: https://github.com/stymiee/Authorize.Net-XML. Here is the code that I am using from the sample:
require('../../config.inc.php');
require('../../AuthnetXML.class.php');
$xml = new AuthnetXML(AUTHNET_LOGIN, AUTHNET_TRANSKEY, AuthnetXML::USE_DEVELOPMENT_SERVER);
$xml->createTransactionRequest(array(
'refId' => rand(1000000, 100000000),
'transactionRequest' => array(
'transactionType' => 'refundTransaction',
'amount' => 5,
'payment' => array(
'creditCard' => array(
'cardNumber' => 'XXXX1111',
'expirationDate' => '122016'
)
),
'authCode' => '2165668159'
),
));
I keep getting an error message saying that the card code is missing. Any thoughts on what is missing to allow a refund to go through?
NEW CODE:
$xml = new AuthnetXML(AUTHNET_LOGIN, AUTHNET_TRANSKEY);
$xml->createTransactionRequest(array(
'refId' => rand(1000000, 100000000),
'transactionRequest' => array(
'transactionType' => 'refundTransaction',
'amount' => 1.00,
'payment' => array(
'creditCard' => array(
'cardNumber' => 'XXXX1014',
'expirationDate' => '122025',
)
),
'refTransId' => '4928163616',
),
));

Answer 1

$xml = new AuthnetXML(AUTHNET_LOGIN, AUTHNET_TRANSKEY);
$xml->createTransactionRequest(array(
'refId' => rand(1000000, 100000000),
'transactionRequest' => array(
'transactionType' => 'refundTransaction',
'amount' => 1.00,
'payment' => array(
'creditCard' => array(
'cardNumber' => 'XXXX1014',
'expirationDate' => '122025',
)
),
'refTransId' => '4928163616',
'transactionSettings' => array(
'setting' => array(
0 => array(
'settingName' => 'emailCustomer',
'settingValue' => 'true'
),
)
),
),
));