Poorest service ever!!!!

My car broke down 3 weeks ago after an engine failure and I called Audi assist to tow it to the nearest Audi from where I stay and it was towed to Audi Bryanston. My car is an Audi A5 4.0TFSI 2023 model with 11000km on the clock and it showed an engine coolant warning, which was attended to by pouring water at a filling station and subsequently, the warning light disappeared. After a few kilometres drive, my car engine seized and I parked it by the roadside and called Audi Roadside assistance. After a week without feedback from Audi Bryanston, I called them and was told that my car had not been touched and I was not given any reason for the delay. After 2 days, the service personnel called me to inform me that the report showed that I drove the car for 150km without any coolant and the technician had to strip and check the car, for which I had to pay since it was my negligence. I queried the report and reached out to Audi South Africa for further assistance and I was told that they also rely on dealerships for reports and diagnostics. Out of despair, I agreed to pay the money for the strip and check which was R16000. 6 days later the service personnel called me with a quotation that was worth R48960.00 and I was unhappy since that was the price of a brand new car. I feel Audi Bryanston is taking advantage of me since I do not know anything about cars and because of my profession as well and they want to go to extremes to milk as much money out of me as possible. I need help and I am frustrated. I was told that if I don't agree to the quotation, then they will reassemble the car and I have to tow it out of their dealership as is. I need any type of assistance I can get to fight Audi South Africa and Bryanston for their unfair treatment. Bear in mind that this is 5th Audi I bought from Audi South Africa and I don't feel appreciated as their valued client.