Daylight ******* & Not treating customers faily

Very much heartbroken and disappointed, bought a vehicle which I did not take home with me because of the poor state it was in, rat **** and all, and advised the staff I was no longer interested they said they can only do a buy back as I had paid already and they are offering me 40 % of what I paid when I didn’t even move the car an inch which is still in their premises, why am I being ripped of 62 & of what I paid? I need someone to urgently intervene here