Lack of assistance

I have an amount coming off my credit card every month. I have tried everything to stop it and get no assistance from the bank - this has been going on for more than two months now. I have cancelled the card, been issued with a new one and been assured this debit order (which I do not know anything about) will not run again. I cannot access my own account as I get the message HOT CARD PLEASE RETAIN yet this debit order has run again???? This is MY account and I am not authorising them to pay this - how do I stop this amount from going off? I get no help from ABSA. They sent me a voucher which is supposed to prove I made this transaction - yet I do not know who these people are and when I contact them they tell me they have no record of me! I am not even asking the bank to refund the money I JUST WANT ANY FURTHER TRANSACTION WITH THESE PEOPLE STOPPED - WHY DONT THEY HELP ME?