Enterprise Rent-A-Car

My wife was in a car accident, and We are with State Farm. State farm advised they would set up a rental with Enterprise but that we could go get the car now. She went and picked up a car, at the weekly rate. No one told us that there was a lower contracted rate honored by Enterprise. Enterprise rep was advised of accident. Coverage supplies us with the Burdon of 20% of the rental fee up to $500. Wife rented the car for a week, to the sum of 390.01, which was at their regular rate. State farm advised the rate should be only $25.00 / day due to a contracted rate. My wife returned the car, after hours, and they closed out the rental without her consent, so we did not get the adjustment of the $25.00 rate, which we are owed. Enterprise rep said he can't do anything and said he was sorry, and thats it. This is, theft by taking. Enterprise owes us a substantial amount of money back.