complaint

I took out a cell c contract for two phones early this year, I then paid them off but used one reference to pay them instead of different reference numbers, I then went to the cell c in Ndofaya Mall and asked them to call them to let them know about the mistakes in the reference number we called, made copies of all slips they said they could see one account was in credit with the difference of the other one and they would fix it. I got an sms on the 16/04/2015 from them thanking me for making the payment and advising me my contract was terminated, i left it at that, then they started deducting my account, they took over R8000. I called them they said it was for my contract phone, i explained everything all over again they then gave me ref. number: *** and said they would get back to me, another month end came by they deducted over R8000. I went to reverse it AGAIN!!! Which caused my bank to charge me for the same reversal, when I called they kept telling me the same STUPID story gave me another ref. number ***. I am seriously fed up with the call centre because they keep telling me same idiotic phrase that they will investigate!!!!