Expired contract

I had taken a contract in May 2022 for Wifi. I paid for it and for last year I've been struggling to pay because I was unemployed but I managed to pay it. The sales consultant has been calling for an ungrade and I've told them I don't need an upgrade because I am not using the simcard anyway because I am using Rain... So basically I was still continously paying for something I was not even using. I even lost the simcard and blocked it. My contract ended in June 2022 and I managed to pay it. Now there is still money MTN want to deduct for my bank account and it is more than what I was paying for. I have called so many times for a cancelation of my contract but no luck. Last week a MTN consultant called me for an upgrade and I told them I don't need one and explained why and I am in Arrears, the consultant said I owe MTN nothing and I thought it was sorted out. But come month end I must pay two months. I'm very furious because it's not fair to owe something you're not using and the contract has ended on top of calling 100 times for a cancelation. After 12 years of using MTN I am fed up and I will change to another network provider.