Poor Service, ***** and dishonest by MTN

I have been in a 24 months contract with MTN and I have been paying R588.68. for the past 24 months. This contract officially ended in 06 December 2020. -On the 25th of November 2020 I was charged R790.62 with no valid explanation; -On the 18th of December 2020 I sent an email to MTN to officially cancel the contract I had with MTN and requested my number to be converted to prepaid, even though I knew it terminated on the 06th of December 2020 as they were continuing to billing me ridiculous amounts with no explanations; -After this email I was given reference number ***; -On the 25th of December 2020 I was charged R 1447.01 ,when I enquired about this bill I was told it is because I am no longer under the contact. I found this to be the most ridiculous reason, because I had no new contract or cellphone from them, yet I am now being charged double of what I was paying for the past 24 months and I had not entered into a new agreement; -During and in between I was calling the MTN 083 135 customer number which never gets answered; -On the 04th of January 2021 I enquired if my contract was fully cancelled as per my request on the 18th of December 2020;and -On the 06th of January 2021 I received a response telling me that my request has been sent to retentions and I have been communicating with them ever since and yet nothing is happening; -On the 06th I received an email from retentions Edith Itshegetseng requesting retentions staff to migrate my number to prepaid which is still not done till now. I am exhausted from trying to get MTN to cancel my contract and to stop billing me. -No Supervisors are ever available to attend to my query; -Every time I call I get told that a Supervisor will contact me and my contract will be cancelled, but it never happens; and - Till today my contract is still active and every month I am being charged R 1447.01