omg I'd be so furious. She had no right to do that.
If you post pictures maybe we can help you fix it. All you really need is a pair of hair scissors and thinning shears, you can get both at Sally's.
You might have to reteach her to accept grooming, if that's the case just brush her as usual and build up to a few snips. Make to tell her she's beautiful.
I had Lola groomed by a groomer once, the cut was horrible, she blamed it on 8 month old Lola, and I had to reteach Lola to be groomed.