Poor service at Cartrack

I have a contract with Cartrack, since 2021, I've traded in my old car, I called them and asked them to come and remove the device from the old car to the new one, the lady I was talking to told me that the scheduling department will call me back. They did call me back after a week, and by that time I had already signed a new contract with the new tracking company. They are still deducting my account, when I call them for clarity, the consultants are rude. I don't understand how do I pay for a service I no longer receive.