I'm going to cut her hair in revenge
Why would you cut her hair for revenge?
She's got that new hair style that I just hate
I don't understand your reasoning behind getting revenge on someone because their haircut displeases you. It sounds petty, to say the least.
It's not petty, she's got a good haircut and I hate it.
Do not seek revenge because you are jealous of her hair. Do not be jealous of someone else, it will only cause you suffering.