Most Helpful Girl
At least in this situation she has been straight-forward enough to let you know that she doesn't want a relationship.
When she encourages attention from you it's probably the furthest it will ever get with her.
Just enjoy what you do get from her and don't take it too seriously, and if that's not enough then find someone else because she's made it clear what she wants and it probably won't change
Most Helpful Guy
You need to let her go, and seek someone else who is interested in a relationship with you. It's pretty clear that this girl lied about having feelings for you. She just wants to enjoy with different guys.