Same shit happened to me and I did nothing wrong.
Exchanged playlists with this girl, met for lunch a couple times, took her out for froyo, went back to my place to watch a movie, went to kiss her and she gave me the friend zone speech.
She asked if we could still watch the movie and I was like no you don't get to watch the movie and drove her home (should have made her walk).
She said I was one of her best guy friends and she still wanted to be friends.  I told her that I wasn't going to be friends with her and I haven't talked to her since.
A couple weeks later I started hooking up with a girl whose way cuter so it all worked out.
Just think of your friend zone experience as dating practice for someone better.
And don't talk to her anymore cause you'll get more attracted to her and be more upset, less confident, and have less time to pursue other girls.
Good luck bro, and remember, the only way out of the friend zone is to fuck her mom.