If they put it on paper as new and it wasn't, get your money back! If you didn't notice there isn't much you can do except read the fine print closer next time, read up at a good site like http://www.carbuyingtips.com so you are ready for BS from dealers and lastly, don't shop in person at a dealership - fax 'em. Fax lots of them. Make them compete for your buisiness. Dealing with car dealers in person sucks - as you now know

Learn from your mistake, get educated and don't repeate it