GOODBYE MTN!

My experience in trying to cancel an MTN contract has been dismal. On 14 Oct 2022 I called MTN to cancel the contract which was taken in Nov 2020 (24month contract), R405 debit order monthly. The billings department only processed the cancelation on 11 Nov 2022. So on 15 Nov 2022 my account was debited for R405 (fine), due to their delay in processing. But, on 15 December my account was charged R464.92, apparently its a device cancelation fee. Now my issue is a 24 month contract would run from Nov 2020 to Oct 2022, so my last payment should have gone off in Nov 2022. I did my due diligence of calling the a month before the contract was set to expire however mtn delayed in processing, and I was only changed from contract to prepaid on 11 Nov 2022, so then why was I charged in Dec 2022 for a service I did not receive in Nov 2022, as my data/minutes usually refresh on the 12th of the month, I was already on prepaid. Furthermore, when I made the call to MTN to cancel, at no point was informed that I would be charged a device cancelation fee. I've tried so many times since the debit went off on 15 December 2022 to date to get a hold of a competent MTN 'champion' to find out why I am still being charged passed the date and why was I not informed of device cancelation charges and to request the recordings of the contract cancelation only to be faced with a series of dropped calls, and incapable transfers between staff in customer service, billings and retention departments. How is it that MTN can now just have free reign over our bank accounts an debit unspecified amounts without notifying us.