Inability to cancel my contract with MTN

I have been trying to cancel my contract since end of 2021. MTN convinced me not to cancel and promised to courier a new sim card to my address I provided - on two separate occasions. All the conversations I had with them is on the system and the consultant confirmed what I said..... again promissing to send me a new sim which again has not arrived. It is months later now and MTN debits my account every month, oh and not to mention they increase my premium when it was due to be increased not taking into account that I NO LONGER WANT THE CONTRACT!!! If I cancel my debit order with bank I am the one that ends up with a bad credit record for not honoring my payment to MTN, yet they are not honoring me as a client in anyway shape or form. What must a person do to have a contract cancel with this company??? MTN, if you know what is good for you, you will contact me and sort cancel this contract once and for all. I have lost all faith in you as a company! Wilene Smit - ***