Distasteful unsatisfactory customer

I have had a very distasteful experience with hoopers vw durban, they gave me a car with major faults on it , just driving it twice I had to take it back, literally in 7 days ,then they agreed to take it back and picked it up in 15 days and resold it ...i was going to take another deal...but had doubts about it and the dealership and requested to withdraw from another deal and when i requested my refund of my deposit they refused and said is going to be kept for cost incurred on their side . I have not signed a otp for another deal nor did i pick it up from the dealer ....how can their faulty car become my cost to incure ,were they couldnt do their job in the first place,giving me a terrible experience of driving a new demo car, because im a lady they take women for granted, were i picked up something was wrong driving it twice yet the sales person couldn't pick it up but drove the car few months . The sales director says there no such thing as cancelling a deal. What about CPA? To a dealer i am just another profit but to a customer, it took hard work to save up for a deposit .I have been brand loyal and driving vw over 15 years. This is the type off treatment we get ! Utterly disgusted with their business ethics . Would never ever recommend them to any one !!!!!!