Extremely poor service Cartrack

Over a year ago, a cartrack technician installed a unit in my car & my car wouldn't start or open after that. On the same day, I called the technician back & he had to break my window to gain access & fix whatever he messed up. Before breaking my window, he assured me that cartrack will contact me to replace my window. To this day, it has never happened. Since then I've spent so much airtime calling Cartrack & logging enquiries (and also via their website) which they acknowledge but never resolve. They always promise to call me back but never do. I have since fixed my window & have asked numerous times for a contract termination. Again, they always promise to call me back but NEVER do, not once. In the meantime, they keep debiting my account despite my vehement disapproval. I really wish someone can resolve this matter so we can terminate the contract, this has been on going for over a year. The worst customer service I have ever received in my life.