Wow. They really screwed things up. This is just me but I'd put the issues in writing, specifically describe the remedies you expect, and set up a meeting to review those with the GM or better yet the dealership owner. Give them a chance to remedy their mistakes (tough to do but possibly easier/cheaper than a lawyer).
If they blow you off there's always the local news (call for action kind of thing that might be worth a shot before a lawyer, or small claims court depending on the size of damages).