Mtn renewed my contract without my consent

I took a data contract with mtn, and in 2023 the contract ended. They then then called me to ask if I still want to renew the contact I told them absolutely not. Only to find out they did not cancel it. 2 years later they are busy calling me telling me I'm in arrears because I'm not paying for the data Sim card. I have been calling and telling them that "I ended my contract with you" . With no success. Mtn is bad service provider. Now my credit record is ruined because of mtn, because they failed to cancel my contract, they renewed without my knowledge. I even asked the to check when that sim card was last used, to check it's activity.