Incorrect billing for months.

I opened up a contract with cell c telephonically, the contract was a data plan for 279. On my 2nd or 3rd month I was debited 839, I immediately called the call center and I was told that my line was not capped so that is the reason why I used more. I then asked to be advised on what to do as the following month same thing would happen. I called and I was told it's capped. So during the month of February same thing happened and I called again and asked if asked the lady thrice if she was sure if my line was capped and wouldn't be charged extra again, even dialed *147#. And then was dented more than 279 for March today again I'm being told that I exceeded my limit once more so I will be pay more again for the month of April. I then call the call center again and I'm told that the contract is still uncapped and I should call on the 1st of May to cap it. I'm so tired of this **** as it's an ongoing process I have to call every day on top of that I'm not even finishing the 30G data each month it even forfeits. I'm really ****ed, I won't be working for cell c to be doing there own things...