Whoah, bad move my friend!
You should have told her in person. They tell you that advice for a reason, even though it may be harder, there are MANY benefits.
For starters, since you told her on facebook or on MSN, SHE has an option to reply to you or not. If you call her, SHE has the option to say "Oh listen, I have to go." And all three of those instances, you don't know what is going on.
If you saw her in person and explained to her the situation, you could actually see how she reacts and be able to talk to her about it.
So what do you do now? Let it go. If it is anything I have learned about women, it is that the harder you try to get them back, the more it does the total opposite.