If you haven't already, I would recommend doing a "Factory Reset". I know, it sucks... you'll lose all your apps and your phone will be as if you just bought it again. However, I've found that doing so tends to fix the errors that come with updating as updated can sometimes leave old versions of files behind which may or may not be compatible with the new updated version of Android. These left behind files can sometimes cause system or user apps to run incorrectly, cause random reboots, and all other sorts of weird errors. If you still have problems after a factory reset, then of course, take the beast in and tell them your issues. You'll get the run around unless you can show them what it's doing right in front of them, but 'tis the nature of the beast that is carriers.
Good luck!