Disappointed and drained

I bought a car from the dealership in January, under the premise that it was a "Demo" vehicle. I traded in a vehicle, for which they settled the balloon payment. 2 weeks later, I found a report in the car, which to me looked like an accident report. I went back to the dealership and spoke to the salesman and the manager who told me they had no knowledge of the car being in an accident. I didn't at this moment realise that the car was actually, a trade in and not even the dealership demo. I drove the car for 8 months very unhappy until I had a puncture and could not change the tyre because of the incorrect lock nutt. I was very upset as this was at night and thus resulted in me writing an email to the salesman and copying the principal dealer. A meeting was set up between me, the manger and the principal dealer in which the agreement was they will arrange another car for me. I agreed to this because a car is crucial for my line of work and I did not want the stress of looking for another car. I made it clear in the meeting that I did not trust them. This was done. A week after I received the 2nd vehicle, I informed the salesman that there is a funny sound coming from the rear end wheel of the vehicle and the start- stop function doesn't seem to be working properly. I was dismissed with the comment that it is how I drive the car. The salesman drove the car with me for less than a km and could not hear the sound that I was referring to. 2 weeks later I still hear it and the start-stop functionality has not changed. The journey for me with the dealership has been emotionally draining and I honestly hate Audi right now, with all that I am. I want nothing to do with the brand.