..but maybe not by her!
AGH. Just going through end of relationship, terrible times all round.
Asked for golden toned very subtle balayage on my blonde hair. Have been to this place many times before, originally I took a photo to show them what I wanted, but each time they nailed it so didn't bother. However, my usual hairdresser has left and this was done by someone else.
I have been left very obvious chunky highlights which are ash coloured on top of my normal hair, with a particularly unflattering stripe of what looks like grey on one side. She just used bleach, and now I'm wondering if my usual person used something else - different tones? I didn't bother asking as trusted her and know nothing about hairdressing!
It's aged me by about a decade! I've paid so much to look a million times worse than my usual (shoddy) appearance 
How do I politely explain this to her?