PayUMoney — Deducted AMC Charges without any notification

I got the payment gateway activated approx 3 years back but suddenly without information they deducted rs. 5900 form the account saying that this is AMC. I wasn't even informed about the same. On the other hand they mention on the wensite that there is no any AMC Charges for the customers. They charge as per the transaction. Here they are charging on every transaction and without any information they deduct the amount that is not ethical. Please help me get my fund refunded. I am attaching screenshot of the deducted amount and The promise they make that there is not any AMC.