"Ok fine so when are u available."
BIG mistake. And, as expected, she gives you THE most classic excuse of all for a woman: I am busy.
You know dam-n well that is bullsh-it. No girl is busy at every single hour in the week. Even if she is busy, that doesn't mean she never has time for lunch, dinner, fu-cking off with her friends, etc, because she does. She thinks she has control of the situation, which she pretty much does at this point. Anyway man, I don't need to go on and on about it, but you know as well as I do that it is her way of blowing you off, telling you she isn't interested basically. Women don't seem to understand that men are very easily "led on" so they will give little hints here and there thinking you get the point, but most men don't... it would be much better if they just directly told us they weren't interested. I won't think she's a bit-ch for not liking me or anything, but I have felt wronged by women when they flake out on me just as you described.
Now, as usual, it is possible she is testing you, as women do, but I don't think flaking on a planned date would fit in that category in most cases. I probably wouldn't have even called her after that. You know what I did once when something similar to that happened to me? Well, first, it was a different situation, but basically the girl invited me to go to a thing "with" her and while I was there, there was no "with" involved.... she paid me absolutely no attention, talked to her friends, and ignored me. So what I did was I left before the thing was even over and got the hel-l out of there. I swear to you, not 30 minutes later, she called me from her cell while she was driving home. Yeees, kinda a shift in power there right? She was apologetic, exactly like that girl was, but as I quickly discovered, she was an attention who-re, so I didn't pursue it any further. Later that same year, months after our last telephone convo, she saw me with a group of other girls (friends) and just wouldn't stop staring at me.
Basically, you need to cut off all contact with this girl and don't call her again. She did you wrong, for whatever reason, and the only right thing you can do at this point is to forget about her.
Remember, "busy" is bullshi-t. If she ever does call again, YOU tell HER you're busy, then see what happens.