03-21-2013 01:33 PM
Hi and Welcome to the Community!!
With a strong carrier signal (e.g., not WiFi), I suggest the following steps, in order, even if they seem redundant to what you have already tried (steps 1 and 2 each should result in a message coming to your BB...please wait for that before proceeding to the next step):
1) Register HRT
2) Resend Service Books
3) Batt Pull Reboot
Hopefully that will get things going again for you! If not, then you should contact your mobile service provider for formal support.