Poor service

I have honestly never had a bad experience with a company like this. Cartrack keeps telling me I have two vehicles when I only have 1 car fitted with a tracking device. After paying my premiums I have now been charged 3422 for back dated adjustment for a unit I don’t have. My debit orders have all bounced due to the incompetence. I want my money back and I want to cancel this service because I call and no explanation is given.