MTN

I am very disappointed in the service received from MTN I had a contract with them which I canceled however, however the agent assisting me never canceled the insurance not sure how do I have insurance on a device I no longer have I ended up paying over 6K in August 2023 as I was default with MTN I received a paid-up letter. Yesterday 03/04/2024 I went onto clear score only to find that there is an outstanding amount on my name after receiving a paid up letter. Not sure what I need to do in order to close off my account with MTN.