Cartrack is offering a pathetic service, what they care about is our monthly premiums

Cartrack is offering a pathetic service, what they care about is our monthly premiums. I sold one of my cars that was fitted with the unit and I notified the cartrack immediately on that day that I sold the car to a certain dealer. So as usual, the cartrack was supposed to go and do the deinstallation and come and reinstall the unit on another car. Which they never did as there were not interested. To get their attention, I went and reversed the debit order that I paid for that month and that's where I got their immediate attention. I then escalated the matter to managers because what call centre agent cared about was that I have to pay for the reversed debit order and I advised them that am not keen on paying for a service that am not benefiting from it. We exchanged email to the extend if being told that I will be blacklisted if I don't bad. I advised them to go ahead and blacklist me.. Up until Molantwa come in and discussed the possible solution and addressed the issue.