Wait, what kind of games is she playing? Some girls act like they're completely disinterested when they're really just f*cking with your brain. Ever watch a sitcom where the extremely persistent guy keeps hitting on the same chick even though she refuses his advances? She typically ends up falling for him in some later episode.
I know that's a fictional plotline, but it's worked for me a couple of times. Just keep workin them and flirting with them, (make sure you're not creepy, that'll ruin your chances), and they'll eventually lighten up. If they give you sh*t, act like it's their problem and not yours. Most women tend to just give up their stupid little games and succumb to your charm.
Like, if she tries to blow you off, or if she makes a smart@$$ comment, just give her the deadpan and say "did you like, wake up on the wrong side of the bed today? lighten up."
The most important thing is to not let it get to you. If they see you're frustrated, you'd have closed the door of opportunity so they didn't have to.