MTN won't terminate my contract

Mtn is still ruining my credit record for a router and data contract which should have been terminated in August of 2023. I contacted the customer service department countless times, asking them to terminate my contract after August, even when I got calls for an upgrade I refused and made it clear that my contract should be cancelled. I also physically went to an mtn store to cancel my contract and find out why my account was not deducted for the remaining cellphone contract.I never agreed to a month-month contract for data I was not using.

How is it possible that I am liable to pay over R4 000.00 for something I did not use? The only thing I am liable for is my cellphone contract for ***which should also expire in May 2024- I also don't know the reason they stopped debiting my account for this contract.

Please investigate this and get back to me as soon as possible