Misrepresentation on Cell C contract

In connection with the above matter, please be advised that in 2013 I app**** for Cell C contract for data usage and I stipulated during telephonic conversation that it should be a top up contract not open line. It started as a top up contract deducting R189 per month (as per our agreement). Then it suddenly changed to a bigger instalment of R2469 per month. When I queried this figure, I was told that it was an open line which was against my instructions. I then requested several times to be provided with a copy of our telephone recording for this transaction and that never happened. I feel I am being treated unfairly because nobody informed me about any change on my contract. I demand that you look at this matter urgently or I will have to escalate it to highest authority.