JACMAN: Bring a gun to a knife fight... Not literally... But if you live in a town that has a BBB (Better Business Bureau)... Call them and explain your issue... But also make arrangements to stop by their office to get the business card of the BBB rep. even if he / she says she cannot help you right now...

When you return to the dealership to discuss the problem with the manager, hand him the card of the BBB rep. and just let him know you met with the BBB rep. even if you just went by there to pick up the card...

This should get his attention...

PS: Get the managers card while you are there and just say that the BBB rep. requested it... That should solve the problem post haste...