Trouble at work?

I work at starbucks as a barista...I love the job...But there is one girl who works there as a manager she is a very young 24, and a *****...customers complain about her weekly and she is rude to her fellow employees...This starbucks is not a licensed store, else she would be out of here.. I am tired of her crap but noone does anything about it...I had a confrontation with her today and I had to use my all not to punch her in her friggin head...What should i do ...what would u do ?EVERY HATES HER...yet she is still here, and causing the store to lose money, because of her rudeness!