Was happy with the whole process but have since di...

Was happy with the whole process but have since discovered the agent who sold us the car LIED to us !! He told us we could finance the car then pay it off with our credit card ( we get airline miles so wanted to purchase this way ) when I tried to pay it off , found out you can not use a credit card !!! Now paying finance charges on top of purchase price !!! Very unhappy. Will be contacting the manager !!!