MTN loves to take your money even after you've returned a device!!!

My story starts in 2022 when I called by an MTN 3rd party company to sign up for a Home FLTE 10Mbps Uncapped service at a good price because I've been a loyal MTN subscriber. I receive this device and immediately attempt to set it up. The network is terrible. Within 7 days (cooling off period) I return this device. Yet MTN has debited me for the last 3 years! Nobody has a record of me returning this device. The contract has now come to an end and the pain I am experiencing to cancel this contract is ridiculous! Be warned out there!