2004 Cadillac Deville lied and over charged me

Did you authorize repairs from them, and did you sign a repair order at the time of write up? Have they have the vehicle for an extensive amount of time after repairs were authorized and performed, vehicle completed? If you signed a repair order, that makes you liable for repairs performed, and gives the facility the ability to lein the title of the vehicle for unpaid debts. You should also have been given a written, or verbal estimate for the necessary services, and that information should be documented. Is this a facility that you have patronized in the past? If it gets too physical, you might seek assistance from the better business bureau.