Well, you handled your business correctly, IMO, but the reason she did that is women (some, not all), like to have a bird in the hand, if I may. In a woman's mind, once she knows you have feelings for her, you become the "ace" up her sleeve. You're the guy, (not boyfriend or husband) that buys her birthday presents, takes her out from time to time, goes to the spot where she has a flat tire, or picks her up when she needs a ride, etc. etc. etc - the list goes on and on - basically, being used. You're hoping that one day you'll get at least a peck on the lips or a spark or something - and it can drag out forever, or until you decide to cut it off.
Dude, I've seen guys like that my whole teenage-adult life - with my girl cousins, my aunt, hell, even my three sisters. I always felt bad for those dudes.