********** charges on a canceled account

I have requested to cancel my contract since December 2020, with a consultant telephonically, this was not done and I was overcharged R539 for data I did not use or agree to. I started email communications in Jan 2021, was called back by MTN to cancel, still not done. I was again sent a statement in Jan and charged again R539 for data I did not agree too or use, then the same in Feb and now again in March. My original contract was for R239, I receive emails for upgrades and offers for the same amount of data for R79 per month, yet am being charges for the past 3 months R539 for a contract I canceled in December 2020. No response from MTN, no sense of urgency, while you **********ly charge my bank account without my consent. I want this account canceled, my number intact and I want my money refunded for the past 3 months charges.