Why was this girl so cold to me?

I liked this girl but we didn't know each other and I got transferred out of Biology ( the only class I had with her) but it was a week into the second semester so she kind of knew me. I messaged her ( FaceBook) one night saying I did by accident trying to IM my friend instead and we talked a little bit. It went well. A talked to her a few more times on FaceBook that week and on the Friday of that week I got a friend who was also a friend of hers to tell her I thought she was cute. I talked to her on Facebook about it later saying ';Sorry'; and she said '; Oh no don't be';. Then she told me ';Happy Birthday';(this was three days after my b-day). I talked to her more the following week and I waited in the hall one day for her to pass before my last class and I said ';Hi'; and she said it back and we were both smiling and happy and everything. That happened on a Wednesday and the following Friday I was talking to her on Facebook and I asked her out(yes I know it should have been in person). She said No very poliety and I kept begging I even said something like ';I know I don't stand a chance but your bueatiful and smart and I just really like you'; and she said ';Aww thats soo sweet I just don't know you well enough you know';. Two other of my friends were IMing her too and she said she was kinda uncomfortable with this so we stopped. I apologized in person a few days later and she said it was fine. She was very short with me. As the weeks went by I still liked her a little bit but it had diminished alot. She started going out with this guy and everytime she posted ';I love him'; it hurt alot. She finally dumped him and I felt a bit releaved athough I was sort of over her. Weeks later someone ive known for a long time stopped me in the halls and told me I should try again (he was also her friend). I talked to her best friend on FaceBook one night and she said she thought I could get somewhere although she was still upset over her previous boyfriend. I hadn't talked to her yet but one day something happened. I was walking with my friends and her friends were there too talking to me. I see when she was walking towards me she kind of turned the other way. Her friends directed her towards me and one of my friends was forcefully pushing me towards her. Her friends were dragging her too. I yelled ';Hi'; but I don't think she heard me. She ran away to the bathroom and my same idiot friend followed her. I threw my stuff there so I would have to go talk to her. Her best friend the same one from FaceBook went on about how that wasnt right of me and a bunch of other ****. I apologized to her in a letter on FB and on her wall. She didnt respond to the letter but she commented on her status saying it was okay. I tryed to apologize in person the next day and she simply speed walked away. This happened many times. She stared at me and even called my name and when I went to go apologize she walked away. I felt awful. Why? Why did she do this to me?Why was this girl so cold to me?
Why don't you ask her? Also why would you be in love with a girl who is cold toward you? You should find some one who would treat you better.....sorry my advise probably sucksWhy was this girl so cold to me?
You need to just give her some space...