Shocking - No Service

I still have a contract with cartrack, I've traded in my car, phoned Cartrack they've given me a reference and someone will phone me to arrange for the unit to be removed from the old car to the new, this is more than 2 months ago, still no feedback from them, but they phone me weekly to sell me another contract when I state that I'm still waiting for them to remove the device which is probably not possible anymore as the Dealership has sold my previous car with the device, but they are quick to take the debit order every single month with out fail without actually giving the service as they promise. My concern what if I'm hijacked, they would not even be able to respond!!!!