Im so glad you never paid her!!!!
It too would be bloody livid
I do my own grooming, you could give it a try next time im sure your gonna make a much much better job than this butcher did!! and its not as difficult as you would think.
If i ever succumb to a groomer i have one locally that i would use as you can stay with your dog as he/she is being done then you can keep an eye on proccedings, maybe you could look for a groomer that lets you stay too?
His coat will grow back before you know it, in the mean time time buy him a nice jumper.