PayPal не возвращает никаких переменных после успешного завершения транзакции

Я пытаюсь получить значения на странице возврата после успешной транзакции из PayPal.
Я уже включил автовозврат и указал для него URL.
Мои коды работали ранее, он показывал все значения, но внезапно перестал работать и теперь просто возвращает пустое значение.
Пожалуйста, имейте в виду, что я довольно новичок в php.

Вот мои коды:

<form action='https://www.sandbox.paypal.com/cgi-bin/webscr' method='post' >

<!-- Identify your business so that you can collect the payments.  -->
<input type='hidden' name='business' value='[email protected]'>

<!-- Specify a Buy Now button.  -->
<input type='hidden' name='cmd' value='_xclick'>

<!-- Specify details about the item that buyers will purchase.  -->
<input type='hidden' name='item_number' value='". $offenceid ."'>
<input type='hidden' name='item_name' value='". $offencetype ."'>
<input type='hidden' name='amount' value='". $charge ."'>
<input type='hidden' name='currency_code' value='SGD'>
<input type='hidden' name='rm' value='2'>
<input type='hidden' name='return_url' value='http://mp25.bit-mp.biz/paymentReturn.php'><!-- Specify the Pages for Successful payment & failed Payment-->

<input type='hidden' name='return' value='http://mp25.bit-mp.biz/paymentReturn.php'/>

<input type='hidden' name='cancel_return' value='http://mp25.bit-mp.biz/userFines.php'/>

<!--  Display the payment button.  -->
<input type='image' name='submit' src='images/paynow.png' alt='PayPal – The safer, easier way to pay online'>

</form>

paymentReturn.php

// STEP 1: Read POST data

// reading posted data from directly from $_POST causes serialization
// issues with array data in POST
// reading raw POST data from input stream instead.
$raw_post_data = file_get_contents('php://input');
$raw_post_array = explode('&', $raw_post_data);
$myPost = array();
foreach ($raw_post_array as $keyval) {
$keyval = explode ('=', $keyval);
if (count($keyval) == 2)
$myPost[$keyval[0]] = urldecode($keyval[1]);
}
// read the post from PayPal system and add 'cmd'
$req = 'cmd=_notify-validate';
if(function_exists('get_magic_quotes_gpc')) {
$get_magic_quotes_exists = true;
}
foreach ($myPost as $key => $value) {
if($get_magic_quotes_exists == true && get_magic_quotes_gpc() == 1) {
$value = urlencode(stripslashes($value));
} else {
$value = urlencode($value);
}
$req .= "&$key=$value";
}// STEP 2: Post IPN data back to paypal to validate

$ch = curl_init('https://www.sandbox.paypal.com/cgi-bin/webscr');
curl_setopt($ch, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_1);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $req);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 1);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 2);
curl_setopt($ch, CURLOPT_FORBID_REUSE, 1);
curl_setopt($ch, CURLOPT_HTTPHEADER, array('Connection: Close'));

// In wamp like environments that do not come bundled with root authority certificates,
// please download 'cacert.pem' from "http://curl.haxx.se/docs/caextract.html" and set the directory path
// of the certificate as shown below.
// curl_setopt($ch, CURLOPT_CAINFO, dirname(__FILE__) . '/cacert.pem');
if( !($res = curl_exec($ch)) ) {
// error_log("Got " . curl_error($ch) . " when processing IPN data");
curl_close($ch);
exit;
}
curl_close($ch);// STEP 3: Inspect IPN validation result and act accordingly

if (strcmp ($res, "VERIFIED") == 0) {
// check whether the payment_status is Completed
// check that txn_id has not been previously processed
// check that receiver_email is your Primary PayPal email
// check that payment_amount/payment_currency are correct
// process payment

// assign posted variables to local variables
$item_name = $_POST['item_name'];
$item_number = $_POST['item_number'];
$payment_status = $_POST['payment_status'];
$payment_amount = $_POST['mc_gross'];
$payment_currency = $_POST['mc_currency'];
$txn_id = $_POST['txn_id'];
$receiver_email = $_POST['receiver_email'];
$payer_email = $_POST['payer_email'];

}
else if (strcmp ($res, "INVALID") == 0) {
// log for manual investigation
}

Спасибо.