Terrible service from account to technical department

Terrible service from account to technical department. Every month I've been testing my device and it had not been working for the last 4 months. Numinous calls and being pushed around, they would get it running for a day and it would go off again. Now that I have had enough and would like to cancel they ask that I pay for the device. Which I asked to come and remove as I've been paying for a service that has not been working. This is a huge issue had the vehicle been ****** my insurance would never pay me out as the device does not work which would have been my responsibility.