Poor Customer service and incompetence

I sold my first car then asked for de-installation and reinstallation in March 2024, they debited an amount of R840 for that end of March. I had to follow them around for the process, the device was deinstalled on the 6th of June 2024, until today the device is still with them not in my new car. I've sent emails and spoke to 4 consultants requesting for the device to be fitted into the new car. They kept deducting the monthly fee, I only started receiving calls from them when I stopped paying for services i was not receiving. I have been threatened with legal actions yet they still haven't installed the device. Now I must pay over R3000 to cancel yet they have the device. Such incompetence is shocking.