How to receive POST data in django

I've been trying to integrate a payment gateway into my site in django. I'm having trouble getting the response data from the payment gateway.

The payment gateway has sample docs for php which looks like this :

$ErrorTx = isset($_POST['Error']) ? $_POST['Error'] : '';               //Error Number
$ErrorResult = isset($_POST['ErrorText']) ? $_POST['ErrorText'] : '';   //Error message
$payID = isset($_POST['paymentid']) ? $_POST['paymentid'] : '';     //Payment Id

In the view for the url that the payment gateway is redirecting to after entering card details etc, I'm checking if it's a GET if request.method == "GET" and then passing the request to a function. When I debug the request, I can see an empty query dict. and if I try something like res = request.GET['paymentid'] I get an error that says there's no key called paymentid.

Am I missing something obvious? I'm still pretty new to django, so I'm sure I'm doing something wrong.