Avis car sale

I bought a car at avis at 35000 milliege it was after some weeks i realise that the car have two colours and the car was not working properly seats rails had ruts then avis refer me to the s**** yard only to find out that the car was involved in an accident i ask them to exchange the car since i was experiencing new problems day by day .they refuse and told me to trade in the car now i have to pay a short fall