Two months without my car

Jan 2015 I decided to change insurance company to King Price as they had the best offer. On 15 April I had a fender bender. The guy did a U Turn and drove head on into the front and left side of my 2013 Audi A3. I phoned King Price and the car was taken away on a flatbed as it was not drive able. It then took 2 weeks for an evaluator to look and assess the damage. Finally the car was taken to CK Coachworks and then took 4 weeks for the front bumper, left wheel panel and lights to be repaired. I eventually got a call to say i was able to collect my car on 27 May. 6 weeks after the accident! I went to Tokia but my car still had marks and chips in the paintwork. CK Coachworks offered to deliver the car to me in town that afternoon. When they delivered the car the bodywork looked fine. I parked and went back to work. On my drive home i discovered the car had no acceleration and the electronics were giving errors on the on board display. The following morning CK Coachworks towed the car to Audi Claremont, where it has been since. I have been refused a courtesy car after being told i would get one and Audi now can't give me an answer as to what is wrong with my car. I am so frustrated!