Yeah...
I am an expert on...well, probably not *anything* yet in life, but most certainly I'm not an expert on women.
And even *I* can tell--you overreacted, sir.
If there's one thing I've noticed from years of having girls as friends--well, among other thjings--it's this:
If you set a date to meet, you--the guy--will most likely try and be as prompt as possible...she'll likely be late, and think nothing of it, and come smiling along as if 10:30 were no different at all from 9:30. ;)
Same goes with social networking--send a guy a message, and he'll probably get back to you as soon as he can, to get the matter done with.
With a girl--you can send her a message and she'll either A. Wait quite a while before responding because...she can, and she probably has her own reasons for doing so, including the fact that generally women are a tad more communicative than men on such social network sites and with texts and the like, and so she could very well have many conversation threads, so to speak, going on with many people at once, and you get pushed to the side, not out of malevolence, but just lost in the shuffle, or B. She's ignoring that message because she does not want to talk to you. Period.
Same thing's happened to me--once with my best friend, and she and I were in the middle of our biggest fight ever, and I probably said something similar to whar you said to her when she didn't respond, as angry as I was at her because of the whole entirety of the fight, and we didn't talk for three months and if it hadn't been for some figuring out as to why things had happened this way (this whole fight was because of something that didn't make sense on the surface for her to be mad about, but once all was revealed, the devil was in the details) we'd probably never have talked again (thankfully, things got resolved there.
The other time was with a couple of friends I knew for four years, was perfectly nice to them, and probably too nice--a rarity for me, to be even nice at all, really--as in time, they just moved on, and I saw the reason why they weren't responding and just let it, them, go...people move on, after all (although I will say this--I've come to the opinion it's a GOOD thing to fight with one's friends, to be a bit combative and not be the over-nice person time and time again, because you sort of get to know one another better that way, and it's a LOT stronger of a friendship if you know you can and have fought before and things won't blow up as opposed to only ever talking about nice things, and then, well...then people move on, and the glass menagerie of friendship shatters. I'm still friends with the girl I had that huge fight with, as good as ever--no longer friends with the two who I was nice as can be to, so yeah...)