Why do women do this?

Theres this girl I met online and I went on one date with, this was two weeks ago, I then asked her out a couple days later, she gave me the runaround. OK, so I figure she doesnt like me, no problem, I can deal with it. But she IMs me a couple times a week and asks how im doing and stuff and recently she has asked me why I have been such a stranger. Why?? I dont like being rejected really, I dont think she likes me and I hate being given the runaround, there are women that say yes I want to go out. So why does she keep imming me?