I purchased a vehicle less than two weeks ago from a dealer in my town. While on the lot, prior to purchasing, we did our due diligence. We asked all the questions. We checked the oil and transmission fluid. We pressed every button. After a full barrage of questions, the dealer told us the battery was going bad, but other than that, it ran amazing, and had nothing wrong with it. We purchased it for $5k cash. After getting down the road, the check engine light came on. So we parked it, and informed the dealer via text the same day. He did not respond. We had to go to a doctor appointment in town a week later, and the engine completely seized. We had to towed to a shop. The engine is not repairable. He said that, even though the oil was topped off during purchase, it was three quarts low. The dealer said this is our fault. That we had the vehicle for a week and should have checked the oil. Standard maintenance dictates that the oil is checked monthly. I only had it for a week and it was fine at purchase.

I was willing to work with the dealer. I gave him 4 options.

1. Refund
2. Replace with an alternate working vehicle
3. Have the motor replaced
4. Have the motor replaced, and we would pay off the motor in monthly payments.

The dealer says he won't fix it or replace it because "you didn't take care of this one. You'll just break the next one. "

He won't do the other options either. He just keeps citing that it was an as is purchase, and not his responsibility.

I have this whole conversation via text messages on my phone.

What should I do? Am I really just screwed and buyer beware, or is there a way to rectify the issue?