We've been to a bad groomer and unfortunately I didn't know any better. I took Loki there about 3 times and he got terrible cuts and was scared.
Now we go to a groomer who grooms at her home and does only one dog at a time. She lets me stay if I want to. Loki runs up to her porch because he can't wait to see her and he isn't afraid of the groomer any more. There are good ones out there you just have to look hard (and tip well!!!)