Unsatisfactory businesss practices

I got Cartrack last year and now sold my car and don’t hAve a car anymore. I asked them to cancel my Contract because I no longer have the car ,I sold it to their associate Carzuka. This company wants me to pay for the full 24months term of the contract just for cancellation and services I no longer use. This is a pure ******* honestly and poor business practice. How can I pay for something I no longer have. I even wrote to their customer complaints they even want me to pay further fees and move the tracker to another vehicle. How do you even do that with a car that is with them.