What recourse do i have if i have been sold a below value car

Irecently [part exchanged my car which had nothing wrong with it and some money amounting to approximately £10,000 for a slightly newer car to arnold clark but the car which i recieved needs quite a few repairs to the bodywork also the repairs which someone seems to already have done has voided the warrenty trading standards dont seem interested at all can anyone please advise as i am tottaly disgusted with a company which i thauht i could trust