Let your sister share with you her experience..
A few days before my secondary school's graduation ceremony/dinner and dance, I went to have my hair trimmed.
My usual stylist was not around. Being inexperienced, I settled for another hairstylist. I said I wanted a TRIM.
In the end, she cut my hair from a bob style to something like boy-cut!
I wanted to cry there and then, but held it in as I hastily paid for the TRIM and stomped angrily away. The moment I got into the cab, I just burst into tears! The haircut was so ugly!
I didn't step out of the house for 2 weeks after that and didn't even go for the D&D even though people offered to chauffeur me and doll me up nicely.
Moral of the story:
Always stop the hairstylist the moment you feel something is wrong.
Never settle for a hairstylist who's not familiar with your hair and style, unless you're feeling adventurous.