Why she did that?

I like a girl where I work a year ago and now she is going back to her country, the thing is when I met her, I got to know her,she would glance at me all the time and get jealous from other girls. When I asked her out, she told me she was busy, I back off and a few weeks later I asked again and she told me the whole I don't want to date, I'm not ready for a relationship thing so I stop pursuing her and I just say hi and that's it but she still glances at me and everything, now on her last day at work, she completely ignored me and started talking to this guy a few feet away from me and talk really loud, then hugged him and said a hmmm really loud, I got pissed from seeing that I just continue going where I was heading to. What gives?. And know I can't stop thinking about it and still hurts me that I will not see her again even though she didn't wanted to go out with me.