Regional Hyundai

I bought a truck from them and traded in my old truck here recently. I asked the salesman (who was recently fired) what the price was on the new truck and he told me $22,911. They were going to give me so much for my previous truck and before they even laid eyes on it they told me they would give me $8300. After I gave them all the specs of it, they said maybe $6000-$6500. As I continued towards buying the new truck, I was really aiming for my payment to be X amount of dollars and they said I would get a great deal on the truck. Turns out, after looking at the contract a little more closely, I noticed that the actual asking price of the vehicle was almost $5000 more. On top of that, something I noticed while test driving it but didn’t think much of it, was a vibration in the truck once I got it up to 55 or better and it pulled to the right. They took a look at it and rotated the tires and balanced it. After 2 hours of sitting at the dealership, when they said it would only take an hour, they said there was another issue. They told me there was a dent in the driveshaft and said it was 4000 miles old. 1) how do they know it’s 4000 miles old and 2) I had had the truck for 13 days. The thing I didn’t think much on I should have said something about before I bought it. That’s on me but the damages themselves are not. That’s crap.