Very bad customer service

Netstar has the worst customer service. I had bought a car few months back and Netstar installed their tracking device on the car. The car was faulty and I returned it for a different one. Netstar removed the tracker from the older car more than 2 months back and still have not installed it into the newer car. They are still deducting their monthly premiums from me for zero services rendered on their side. Everytime I call, they say they will assist me and send a technician but it never happens, this has been happening for 2 months. This matter needs to be resolved asap because the insurance company I use needs a tracker installed for theft and highjack cover