You deserve respect from your friends, and you deserve to have them treat you the way you treat them.
That being said...when you do something good, you shouldn't do it expecting something in return. Friendship isn't about give and take, its about love and respect. And if this girl is someone you love (as in friends, nothing else, lol) then you should consider staying her friend.
That being said...(lol, see what I did...I'm flip-flopping like mad here) there comes a time when people need to be cut off. No one can make that choice but you. There is a girl who I was friends with for almost a decade, and I got to the point where I was done, and that was it. My husband thinks I'm being harsh, but I'm completely finished. On the one hand, I loved her dearly, and part of me still does, but on the other, I got tired of feeling like crap around her when she needed a whipping post. The final straw was her insulting my mad skillz as a mother, and I haven't gone back. Its been over a year now, and I feel fine. Had I gotten an apology, things might have been different.
All in all, I really couldn't tell you either way. If your gut is telling you something, though, you should listen. Our instincts have a way of knowing what is best for us. Good luck!