It's rough when there is no contact, I feel your pain. Start focusing on what it is that you really want for your life, what are you going to do next.
If you really are her best friend, and she wants to talk with you...she will find an excuse. Four weeks is not a long time, although I know it feels like it.
If she does come back, be a little more careful with your words, try to be a little more understanding. That is also very hard to do.
Proverbs 3:5 Trust in the LORD with all your heart and lean not on your own understanding
