CrackBerry Genius of Geniuses
You did verify it wasn't blacklisted right? Sometimes that might be the case, or it could be a bad sim module. Try a different sim card and see if it works, or without the sim card, and see if you can access the information from the sim options.
Originally Posted by BLINKSMAN
Edit: last resort, try reloading the OS, or update the device software to a later release, if you haven't already did so, but do it from scratch and restore the backup of your contacts, memopad only to avoid any conflicts.
If that doesn't work, bring it to a repair shop and see if they can find out the issue.