Unfair treatment from MTN

MTN is bullying people that no longer want to use their contracts. Once the contract comes to an end, they will not terminate it even after you request it. They will debit your money and pretend as if you have not requested the termination of the contract. I ended my contract in 2020 and MTN is still claiming that I owe them. They have now submitted my name to debt collectors and are threatening to blacklist me.