Ahhhh. One issue resolved. Almost as soon as I finished my last posting I checked e-mail and had a fax from the bathroom people. They wrote a very nice letter explaining a few background situations I had not been aware of and offered a discount on the tile work and the countertop. I'm happy with their offer and am anxious to close this chapter of my life so I left them a voicemail accepting the offer, thanking them for their work (the bathroom did turn out beautiful--I'll post pictures) and I've already written out the check.
What I like best about this scenario is that there is no lingering conflict. I feel like they made the best offer they could to set things right. I can't ask for more than that. And now that I feel like I've been heard and they've addressed the problem, I no longer have a problem. They're welcome to come and take pictures of the bathroom and use the photos for company promotion. I like to think it all worked out.
Big sigh of relief. It's nice to have the book closed on that one.