Loan and Car buiying question

Hey everyone, the other day I went to the local dealer and my fiance and I drove away in a 00 Celica. that's the only good part of this story. We didn't really realize that on the contract there is this service fee, which is a fee they charge for first time buyers, also the price of this car got way out of hand, now we owe about 14,000 for it. We didn't like the way they handled our financing,(just a note, CA doesn't have a cooling off period) The one thing that may help us get out of the deal is that our loan agent had to fabricate information about my fiance to get a good APR, he said that she was a manager at a hair salon when she is actually self employed as a hair dresser, he also stated that she makes 2800.00 a month when she only makes 800.00. If I call the credit union we got the loan through and told them this, will they nullify the loan, meaning we could return the car? Any other insight would be greatly appreciated. thanks in advance
Jeff