Horrible experience

I once had a contract with Cell C until it was finished with no complaints so I app**** for an upgrade I was happy with the amount that I have agreed to pay on monthly basis. But I was very much surprised when the debit goes off for 2 months was more than I expected was supposed to pay(269 if not 279 but I'm paying R483.60 and 417.98 I called customer service i was then told to send an affidavit, ID copy and 3 months bank statement to their ***** department which I did ..I called again for follow-up the feedback I got was that the case is resolved and I was never called then how was it resolved without them talking to me ..I need my refund and the number in question to be blocked permanently so I can continue to pay what I have agreed on .The number in question is ***