MTN overcharging without my consent cancel contract with immediate effect.

I wish to cancel my MTN Contracts with immediate effect. After 17 years they completely broken my trust. 2 months being over charged. This month being over by R8000 never attending to my 1st official complaint. I have reversed the debit order and no longer wish to have any dealings with MTN from this day on forward. Should MTN wish to pursue the avenue to collect penalty fees I myself and my lawyer will be happy to pursue this hand in hand with the CPA . December I complaint being over charged for 1 x 50Gig data bundle which was ordered never received and then cancelled on the MTN Self Service Website. I then proceeded to try and order 60Gig data bundles with the same scenario. I ordered 2 x 60Gig which both never reflected and I cancelled them. I phoned in 10 times and all 10 times I was told they do not reflect so I should not be charged for it. January I got charged over R4000 for these bundles February I got charged over R8000 for double the bundles. I did not agree to any of these and its in breach of my contract and my consumer rights. I'm stopping all debit orders and reversing February debit order as my time with MTN has officially come to an end.