I totally agree with Nancy too!
I was cringing in my seat as I was reading your post! Poor baby!!
How is he doing now? have you had a chance to take him to your vet? I would ask the vets advice too, as far as legal actions you can take. I know accidents can happen, but it was totally negligent for them to not tell you when you picked him up!!
I'm pretty furious over here! You really held it together, I would've totally went off!

Please keep us updated. I'm taking Romeo to the groomer next week and will make sure I check him before I walk out of there from now on!!