That would probably be more hassle than it's worth.
You write a letter to CC company, gather and provide documentation. Shop disputes and sends their own letter. If CC resolution sides with them, you wasted time. If they side with you, shop puts a mechanics lien on your vehicle, now file a lawsuit to vacate the lien and maybe get it vacated or maybe not?
I could see it over a larger amount of money... IMO the best thing that can be done now is warn local prospective customers about their business practices, making sure to use fact supported statements, not libelous.