Vehicle repairs not complete after 4 months

The panelbeater that miway recommended still have not completed my vehicle repairs and its been over 4 months now. The bumper on my car is not fitting flush on the vehicle and they blame miway for approving an incorrect bumper. There is a strange noise in the car that they refuse to take responsibilty for even though the noise started after collecting my vehicle from their workshop. My spare wheel rim has been damaged in their workshop and I'm waiting for them to repair it. I feel my vehicle needs to be re-assessed because the repair work is of poor quality. I am tired of running up and down to this company and arguing with their staff. Is it possible for miway to get my car re-assessed as the work done was of poor quality.