Should I be mad at the groomer?

Is that policy of keeping the money for doing no work written somewhere? If not, and they didn't tell you in advance, then either go back there and demand a refund or report them to the BBB.

I think I'd akin that to me opening an auto store, charging someone to bring their car in for repairs, and then me giving the car back to them saying that I don't know how to fix it but keeping their money anyways.

Absolutely ridiculous.

I have been on vacation, just got back and saw all these responses. In the end, I decided to just forget about it. No, they did not have their policy written anywhere (at least not that I saw). I guess when I asked if they could handle Charlie, I should have asked the question, but they said it would not be a problem so I did not inquire further. See my post about Charlie's week of boarding for an update on his training!