Degusting service - I'm really upset

I am really annoyed and upset with the service of car tracker. On the 3rd of June I paid money into your bank account to have your device reinstalled from my previously owned car to my current one. When I stopped paying that's when you started realizing something should have been done. Only yesterday I got your device installed, on the 8th of October!!!!!!! I am not sure what service you providing but it's disgusting. Now I am not going to pay for the months the device was not installed. My car was not covered by you and if anything had happened you were not going to do anything. Now reimburse me for all the months I've been from July. I am not paying for a service that I did not receive. Why should I be paying for a service I did not receive ??????? Was the device installed in my car ?????? Why am I billed for a service I never got ?????????