After payment I get a 404

[dcaguioa]

I use CCAvenue. I've tried using a Mastercard Credit Card from ADCB bank and after the payment, I get redirected to a 404 but I get confirmation that payment has been received. The items are still in the cart and no order will appear on the orders page. I tried using a LIV debit card from ENBD and the payment went through. The card was also VISA. Has anyone has encountered this before?