Ylg — Looting money

I just got my streaks done and when I went to pay the bill they asked me to pay money even for the hair wash..
I told them that it has to be mandatory because I can't go on the road with foil all over my head .. they replied saying they wasted shampoo and conditioner on my hair so i had to pay for it.
Idk what rule is this ... They are just looting money from common public...