Not a good experience

I recently purchased the wrong G80. How? I wanted the G80 AWD 3.5T Sport Prestige. We test-drove one and the dealer located one to bring in for us. After weeks of waiting and asking when it was coming in, they finally got one in, so we test-drove it to make sure there weren't any rattles or other problems. Then we finalized the purchase and took it home. On the way home I noticed that the head-up display was not working. Then I realized that IT WAS NOT A PRESTIGE. THEY SWITCHED CARS ON ME WITHOUT TELLING ME! I did receive a second quote that was cheaper, but I thought it was because they wanted my business.

Phone calls to the manager resulted in stonewalling. "You bought it!" "You should have known it wasn't a Prestige."

The only thing they will do for us is to take it back in trade at nearly $!0,000 less than we had paid for it the day before.

What recourse do I have in dealing with this unscrupulous dealer?