Is this girl manipulating me or playing with me?? (Girls please help)?

[wololo]

Hi.. I was checking out this girl once when she caught me and from then she seemed like interested in me. I bumped into her several times and finally asked her out for coffee for which I got rejection. She didnt say a straight no, but she took my number and never called back. After like a week I still tried to talk to her but this time she totally ignored me intentionally. (for which I felt like kinda offended). At the moment she also blocked me on facebook. Now its been 1 more week and I noticed that she has unblocked me. I cant send her message or request as it would seem desperate, but I had like really huge crush on her.

Now, i have noticed that we are bumping into each other more than usual. It feels like she takes the same way and is doing it intentionally.(It can be by chance too) As one of my friend said, she just needs attention and thats why she is doing this. What should I do? Please help.