Unfair Debit

On the 5th of May I spoke to lady named Thandi at the MTN Call Centre regarding an outstanding amount (about R1300) I need to pay as my contract has expired. We came into an agreement which she confirmed with her superior that I will have to make a bank deposit of R741.86 on the 27th May which I did and the Balance will be deposited on the 27June....<br> <br> Now the trouble starts after I have kept my side of the deal on the first of June MTN went on and debited R741.86 from my account after I had deposited R850 into their account on the 27May and they had sent me an sms to confirm receipt of my deposit. I tried calling the call centre again to check with them but no answer from the call centre and when I visit the Benmore Branch where I started my contract from they told me they cant help with anything as I have to call the call centre. then again on the 6th of June they did another debit of R488 which bounced and has left me fighting with my bank for charges