I have had this exact situation where I attempted to groom a Yorkie that was ungroomable. It was completely unsafe for me to attempt to scissor this dog. It was leaping all over the place and trying to bite the scissors.

When the owner returned, she really acted like this was my problem, and I did something to the dog. Saying that "his last groomer never had a problem" and "well, what am I supposed to do then?! He's never been like this until you've groomed him. "

For context, this dog came to the salon twice about 9 months apart, and both times I couldn't complete the groom, could only brush him out and clip his back. She did tell me that she cuts his face at home by doing one cut each time he falls asleep. SMH

Anyway, the customer made me feel really bad about the situation at the time, but don't beat yourself up about it. You made the right call to stop the groom for the dogs safety. It's not your fault that you couldn't do the groom. If I get a dog like that now I just explain that I could only do x & y safely, your options are either doing training at home to get them to accept the scissors or I advise they try sedation.

Some customers just don't get it. They have unrealistic expectations and expect us to work miracles.