VERY POOR SERVICE FROM DISCOVERY and repairer of their choice

I had a car accident and Discovery took my car to Springfield Panel and Paint to do repairs, it was returned to me and two weeks after it started over heating then I took it to Hyundai who advised that the car is over heating following a job that was done by the repairer but the repairer and Discovery assessor disputes this. My car has never given me problems prior to the accident. It is now 3 weeks I am without a car, discovery has never called me even once to give me an update, I have to call them everyday and even then I dont get any proper feedback, they keep saying they are investigating. I have to use uber to travel and that is an additional cost to me. I dont know what is happening with my car and why they are allowing the repairer to lie, they are also protecting the assessor who is clearly not doing a proper job. I escalated the matter to two managers at Discovery but I have not received any feedback from them, not even an acknowledgement of receipt of my emails.