FED UP with MTN

I am so disgusted with MTN at the moment. I've been trying to cancel a paid up to date contract. I emailed them March 2022 to cancel my contract. Ever since I have been emailing them backwards and forwards. Finally I ran into an arrears, due to their mistake, they expect me to pay now and I'm handed over to their legal department! See an email below I received in June 2022 from MTN

Dear Valued MTN Customer Thank you for getting in touch with the MTN Customer Care Department. Due to system upgrades, the delivery of your email to our front-facing team was severely delayed. We apologise profusely for this. Please help us resolve this ASAP; If your query has been resolved since you emailed us, you will not need to reply to this email. Should you still have an outstanding query that needs our attention, please reply on this email and let us know that you still need our help. Rest assured: We are committed to resolving your query and will ensure that you receive the service recovery deserved. Thank you for your patience with us during this time. Best Regards, MTN Customer Care Team

So due to their system upgrade my email was delayed and ran into arrears and now I am liable to pay which I disagree with.

I called customer service several times but that's also a lost case!

My cancellation REF NO: ***

I'm just FED UP!