There really isn't getting out of the friend zone. It can happen but its so rare, your best bet is to put your efforts into a new girl.
That being said though, either your not really in the friend zone or this girl is playing you like a fiddle. I don't know many girls who do what this girl is doing who don't want to date you, and those who do are skanks and serial flirts who use guys for stuff like this. I kick them to the curb.
So my advice is to avoid getting int he friend zone in the first place, you need to make your intentions known and do it fairly early on. That pretty much sums it all up. Act like a guy who wants to date and bone her, not a guy who wants to be her friend. You have to make that clear that you aren't interested in friendship.
Also, if this girl in fact doesn't want to date you, then you need to kick her to the curb. You can't allow her to be treating you like a quazi Boyfriend without you getting anything in return. She either is going to commit to you, or this behavior needs to stop. The thing is you told her you like her, which is fine, but you didn't put your foot down after that. She's gotta either go all or nothing. Instead she's leveraging the feelings she knows you have to manipulate you. I've seen girls do this all the time with guys they knew were crushing on them. It's sickening really but they do it. Your allowing it to happen thinking it will bring you two closer and convince her to date you, but it never works.