Here's a suggestion for you cowboy -- take the tractor and a big piece of posterboard with a bright yellow lemon on it to the dealer. Tell him you will park in his front lot and wait there until they fix it. Have handouts to give to any and all who will take them explaining how you were treated. I suspect you might have the sheriff come to see you. Be sure to call the local newspaper to tell them what's going on and ask the dealer how much free publicity he would like.
Your situation is reminiscent of a time I went through a drive through and got a wrong special order which I didn't find out about until I got home to the kids and for which the place was not very sorry (yet). I went back to the restaurant a few days later at their busiest time with the boat behind the truck. I placed my special order -- plain cheeseburger -- and they asked me to pull into the special order waiting parking place. I explained about the boat not really fitting into a single spot with a curb at the front of it. They asked me to pull around. I declined, explaining that I wanted to simply wait for them to get my order correct and that I would be sure to carefully check it this time. The line behind me was getting long and PO'ed. The manager threatened to have the police come to tell me to move. I asked him how it would look in the local paper to have the police respond to a low level call sooner than they could get me a hamburger. He scowled and cussed, but I got my order -- correct and much quicker than if I had gone to the waiting area in a car.
Yeah, I know I was being a jerk to the people in line behind me, but the fact that they either moved to a different restaurant or were very unhappy when they came to the window and had to be dealt with should have served to make the manager and staff know that it doesn't pay to screw up a customer's order.