For me, it wouldn't be THAT serious however, it IS serious!!
Example:
If I've suffered through growing my hair out for 1 to 2 years w/out a perm, to give it a good healthy start, intending to have it permed professionally in the end...
Then I go to a Salon to someone whose supposed to be a professional, and they Over Process it to the point of falling out, I would definitely be upset! Giving me a refund is not going to give me my hair back.
It's not as if I can just go wash the hair style out and get a new one. Once it's ruined I'd have to cut it and start over and I would not be very happy about that.