A car involved in an accident when purchased.

I bought a car with Peugeot Northclif, Peugeot 308 XT 1.6 2009. After 2 months a car started misfiring, I reported a problem which was never attended to until I got a Principal dealer involved. They started fixing g a car which was never fixed properly. They offered a courtesy car while they were fixing a car. I finally noticed that a cat was involved in an accident when I buy it and I was not made aware of. I got them to substitute a car but instead they tried to get me to buy a car of a same make, model and a year. They keep on saying they are looking for a substitute car but it is clear that they are not and are not willing to substitute a car.