Purchase of Used Vehicle and the dealer never mention that it had a problem. On my way home the car started to Jerk and twas difficult to shift gear

Saw a vehicle on Car Gurus, called the dealer. Was told they are Sussex county After a long time of checking car , i got a vehicle with the assurance that it was good. I was on my way home when the car started to jerk on each gear shift. I called the dealer and he said he was with a client and could not talk. Was able to manage it home. Tried the car 2 days later and twas the same and even worse. I decided to try the vehicle on Monday to work, on my way back on the highway the car refused to change gear. I got off the highway to a gas station only to find that smoke was coming from the hood. I called the dealer and he didn't pickup. I sent him an sms and he responded with no viable answer. I allowed the engine cool then managed to drive it home with little or no difference. I haven't collected the title yet but he brought it for me tonight and i refused to collect it and told him that i don't want the car no more. Please advice me on what to do as i am a victim of exploitation. Thanks