Roseville Toyota Changed my contract without disclosing to me.... Roseville California

I should have read yelp about this dealer before I purchased... The comment that fits my situation was " This dealership has a bad track record of lies, check out Toyota Sucks website, I wouldn't have bought here"...Salesman was awesome, I purchased a new Prius V for my wife's birthday, went on line and started the proses with Regent our sales person, he brought cars to my work as I work 10-7 7 days a week, this is not a meager purchase for us, finely we came to terms, we meet to dealership, and made a deal.. “My contract was changed without my knowledge”, it was changed from 72 to 75 months, and the 90 days they were offering on TV we were told if we want that it would not be honored.....The contracts and car were brought to my home to be signed with Regent my salesperson, we trusted and just signed stupidly without reviewing contract, as they never disclosed that they had to change the months to meet my price.. When we discovered the finance manager Tony said they could not meet payment at 72 months but if I want to have the 90 days they are offering we could add 10 dollars a month and .9% to loan, and drop all warrantees, but they could not honor months or the deal that were agreed upon.... TOOK A VERY HAPPY DAY, AND MADE IT A VERY DISHEARTENING DAY!!!!