MTN January Nightmare

I received notification from mtn saying they will suspend my services since my December debit didn't go through. I called them and made an arrangement to pay double for both December and January. The lady who was assisting me asked me if I will pay via EFT or debit, I told her I will pay at the mtn store between 22 and 25 January of which I did in the 22nd. On the 25th they did the debit order. I called them so that they can reverse it, they said they will look into it. They called me the following day just to let me know that there is another debit order on the 31st. To date, mtn has debited an amount of R4300 in my bank account. I only owed them R1500