i am being over charged

i called last month regarding my billing and queried why am i being billed almost R1000 when the renewal contract was for R629.00 spoke to a lady who did not want to give me a reference my number is *** i have had this number since 2001. i asked for my billing statements to be emailed to me nothing of this sort i asked for a copy of my contract nothing of this sort, and requested date of billing to be changed guess what nothing of this sort. based on the loyalty i have given to MTN instead of opting to support vodacom or cell c i feel that this is absolutely absurd i will not pay for something that was not highlighted or explained to me but is billed to me. I request a call from your CEO or CFO to explain the billing and to refund me my overcharge as this is *****. or else we can take this to the consumer commission to rule who is at fault. As far as ruling is concerned i would win and the contract will be null and void as i deal with this on a daily basis and i am talking from experience. oh yes and i am currently barred from getting calls