I would say that they should have fixed it free including supplies unless you did something to cause it to loose its curl. Also unless this is down town Beverly Hills and you go to where the stars go, shop around for service,
I honestly don't know any service my wife gets ( or even complete combination) that could cost 300 dollars. Someone is getting way to over paid to start with.
My wife, ( and you can see her lovely picture at
www.toniklughart.com )
gets her hair straighted every other month I beleive, and some highlights and other things like glitter at times. And seldom is the entire treatment ever over 150.00 For regular wash, ...... rinse and styling it is under the 70 you paid for a tip.
*** OK, from there I will address the other, they should have fixed it at no charge period, not for payment of materials, since the orginal fix was not done properly or correctly.
If they had done it free, yes I would have "tipped" at that point a 20 or 30 dollar tip for the person doing the work. But being asked to pay anything, I would have refused and then not tipped because of it.
Of course as a man, I have only once paid more than 10 dollar for a haircut and you can tell from that wonderful photo that I get every dollar worth.