Poor MTN Service

I noticed that i was being charged for a zero rated SIM card and when i enquired was told that the contract had expired and i needed to cancel the SIM card which i did in October 2020. To date i and still being charged monthly for a number i did not and have not sued. I have sent numerous email to MT with a response that it is being escalated which was months ago. I need this cancelled and reimbursed for all the months that MTN has been charging me.