That kind of thing really ****es me off.
Sounds like grounds for the local investigative reporter. Bad press- advertising can sometimes assist in some resolution, especially if it is part of a larger auto group. They don't like to have the brand/ reputation tarnished, when presented with detailed facts in a proper way. I know from experience that a well worded letter to those that matter,can influence the outcome. The general manager,of a rather prominent dealership, refunded the purchase price back on a used car, once a letter was sent directly to the Owner/ President.
Good Luck,
Jim