i met her and we've hung out
It's fair to say that someone can be interested and for whatever reason, decide that your not boyfriend material. Maybe while hanging out she didn't like the way you ate, swore too much, didn't swear enough (lol), reminded her of her dad or something else? Or it could be a case of her being keen and you taking too long to make your move? No way of knowing, maybe even for her, just it didn't feel right. You can't assume/have expectations of the way things are going to turn out and then feel peeved and mistreated because it don't happen. Don't get me wrong, of course when you are meeting up together and hanging out, both of you with maybe high hopes. But hopes and expectations are very different things.
However now that she has said she just wants to be friends, she needs to stop texting/contacting you so much. As the amount of time you put in together previously, was because you both thought you were heading somewhere. Now that one of you has decided it's not for them, then both of you need to take a step back. If the rejected party (you) wants to be friends sometime in the future, then that's down to you to make further contact, when time has passed. But not just because you're feeling horny or feeling lonely and want to be in a relationship.
You need to inform her that now that your relationship has changed, then you no longer want her to contact you. She might not want this, as she likes having someone desire her, but it's a selfish act and not the way to treat a friend.
I'm coming from the point of view that she is just a regular girl, who fancied you a bit to start with, but as you got to know each other better, she just felt you were not for her. It happens and it's no reflection on you, we all just like what we like, it's like it's built-in thing. Plus we stupidly thing that by saying lets just be friends, it will hurt the rejected party less or we just can't face to tell the truth.
However, as some other's on here have already mentioned, she maybe a bit of a tease, and if so then you need to end contact, as it will mess with your head. Male or female, when in any kind of relationship (not just potential lovers), you should always look after yourself emotionally, as well as physically.
So don't waste anymore time thinking about her or dwelling in feelings of being rejected, she has moved on and you need to too.