Empty promises

My vehicle was repaired in January. The boot doesn't close properly and the bumper needs to be repositioned. I called Re-new-it over a week ago to notify them of this problem. I was kept holding on the phone for over 30 minutes then I was told a service agent would phone me. 2 weeks later I'm still waiting for the call. I called again today and was told the details of my complaint were recorded and a manager was copied in an email regarding my complaint. Again I was promised a call back by a service agent. I tried to call again for a second time and no one is answering the phone. Can someone who actually cares for customers please help me!!!