Terrible pre-owned car quality and service delivery

Not sure who the right individual to contact is as even head office customer care has failed in assisting me. I purchased an Audi A1 Sport-back 1.4t 2014 from Audi Menlyn 9 months ago and the frustration it has given me is unimaginable. For the past 2 months of that 9 months, my car has been to 2 Audi dealerships namely Fourways and Rivonia, with no resolution of the problem but just frustration and time and money wasted. This car has led to me being stranded on the side of the road twice. As far as I was informed by Audi Menlyn last year, the car had a clean bill of health, which is why I am shocked as to why this is happening. I need a resolution ASAP, this is not the car quality I would have expected to get from Audi, especially as they pride themselves in being a premium brand.