Suspended my numbers ***)

I've been using MTN for a long time but now I feel like closing it, they offered me an upgrade on DATA last year December then 2 hrs later I've realized that it's gonna affect my period of upgrading the phone, I called same day and ask them if they can reverse the that they said it's fine. Early January I called again they said it was successfully reversed but now they deducted R13600 on my account instead of R1162 so I had to reverse the amount infact they told me to do so, they even said i musf go to the shop and pay the normal deduction and I did that. When I called asking about this huge amount they said it's the penalty for early cancelation and I told them I've never canceled my contract, now they say it's because only one contract was reversed and still that's not fault they can't charge me that amount and no one told me about the penalty fee now they suspended my numbers.