Pathetic aftersales, only after your Money!

I requested to move my tracking device from one vehicle to another about a month ago. They've called me and messaged me multiple times for payment! Since i have paid them, till now, i haven't heard anything from Cartrack. I dont know if they've already removed the device from the vehicle i have sold or what is happening? As long as you pay them they dont care to even get the work done that you've paid for. They just want your money !