Can I get my hair highlighted again after 1 week having it done twice the week before?

I got highlights and the roots are bry and does not look naural.I went back to my hairdresser and she made it worsr adding more bry hifhlights.I was going to wait a week and go to someone else to fix this mess.How long will this briness last,I have been using purple shampoo and conditioner and it hasnt changedMy hair seems healthy do you think going to a new salon to fix the problem will be roo early.I really wanted to look nice for my reunion.