Whatever you do, just don't let things get awkward. Like nicole said, it's better to be friends.

From my experience, if someone says they don't like you, they usually have someone else that they are interested in, making anything you might try to do to get them to like you useless and annoying (especially if you go over the top with what you try.) Maybe try a little bit, but don't try anything too drastic, and if nothing seems to be changing, then that's probably a sign that you should stop.