More then likely you will need to contact tech support as that is commonly an authentication issue that tech support would have to reset on the system end. Before calling in you can try deleting the connection under Tools>Control Panel>Network&Dialup connections and deleting the National Access-BroadbandAccess or Verizon Wireless VZAccess (or both if you have both listed) and then rerunning the setup wizard under Options>Run Wizard in Access Manager. Also if that dosen't work you can try to connect using NDIS mode under Tools>Preferences and check off NDIS mode. Whether that works or not be sure to go back and uncheck it as that isn't the optimal way to connect but does help in narrowing down where a connection problem is since it bypasses windows dial up networking in establishing an internet connection. If none of the above works you would have to call in, but the fix is usually straightforward and quick at that point.
Hope this helps