Most Helpful Girl
I don't think you should fight at all. I think you should ignore her, try to put her out of your mind, and let go of the whole thing.
She probably isn't intentionally trying to f--k with you, but the bottom line is that you keep getting f---ed with. At some point you have to take care of yourself and stop getting drawn into situations/people that don't make you happy. You can care about someone and still walk away because it just isn't working for YOU.
I'm not saying she is a terrible person, and I'm sure there are plenty of good things you like about her. But she has done enough hurtful things to you that it should make you wonder how much she's really thinking about how YOU feel... people can make mistakes, but someone who truly cares about you won't reject you, block you, ignore you, lead you on, and keep popping back up in your life without even apologizing or acknowledging the stuff that has happened.
I know it's hard, but I seriously doubt she will ever give you what you really want, and it will continue being painful for as long as you allow it to keep happening. Hold tight to your dignity and pride, it's worth much more than someone who already had her chance (and currently still has a boyfriend.)