I bought a broken car. How do I get my money back?

I bought a car from a private individual on July 3rd this year. The seller assured me that the car was full functional and had no faults or defects. However, during the inspection on October 29th, it turned out that the vehicle was in very mediocre method condition and should not be allowed on the road. Is there any way I can cancel this agreement or search a refund from the seller? What are my options?