Try resending your service books.
Go to options > advanced options > Host Routing Table, hit BB button and click register.
If that doesn't do it, you have one of a couple issues. Either you don't have data because of no plan or there is something going on with your service.
You might also try updating Facebook to make sure you have the most current issue.
Also, Facebook itself seems to have some issues once in awhile where the app doesn't want to work.
Hope that helps.