Some people just don't know how to apologize. If you really want to fight it, I would get the address of the president of the company, write him, and include a copy of the letter you originally got.
I can see why you would feel upset, especially since it seems like no one involved is validating your experience. Seriously though, I would recommend just putting it behind you and moving on, because in the grand scheme of your life, it's not going to matter. Who knows, maybe twenty people will read your online review tomorrow and say the exact same thing happened to them. Or the stylist might realize she treated you badly and decide to clean up her act.
I hope you feel better. A good haircut is the best revenge.
