Incorrect Billing

On the 2nd august I lodged a complaint with your call centre regarding an enquiry as to why I'm being billed excessively more than I'm usually billed since I started my contract about a year ago. They said they would have an answer within 48 hrs but this never happened. I have now paid my normal monthly subscription and want an explanation before paying anything further. I called your CC yesterday evening and the guy had no solution to the problem or any answers to my request for an explanation. I ended the call being extremely frustrated. He didn't have a manager available for me to speak to when I asked for one. I was billed several times for large amounts of data being used within a matter of seconds at strange times. When i started the contract I requested the data to be capped and ive never gone over the limit before. Now im being billed approximately R500 more than normal.