Terrible service

I requested them to install the car tracker on April the 5th 2018, and they came same day. However the technician fiddled with my car radio and it stopped playing. I have reported this immediately however the technician only came back to me a week later, in which he still couldn't fix it my radio. His final words was that he will report the matter to his senior technician. Since then, even after several calls to Car track, nobody came. I have no car radio since the 5th of April.