Can I assume this was an email?

You need to SPEAK with someone who can make a decision- the New Car Sales Manager, who can- within a few sentences- understand your value to his bottom line and make a decision within the conversation. Not the sales puke who took your order.

Heck, you might even pitch (depending on how it goes) to him "I am not looking for free, but 100 seems reasonable"... given the part dept cost, he should be able to make it happen