I'm sorry you had such a dreadful experience with Barclay's first grooming. But he's a yorkie and adorable no matter what!
I too have learned my lesson with groomers. One suggestion I would make when looking around for a groomer. Try and find one who comes to the house. We recently found a "Mobile Pet Groomer" and it was a great experience. She parked in our driveway and I was able to keep a close eye on what she was doing. Another good idea is to have a picture of the cut you want.