Download the latest 9320 OS:
https://swdownloads.blackberry.com/Downloads/contactFormPreload.do?code=F50C7035E532C49A0F6993D988E2E843&dl=D15D7EF957AE04B97C3437949ACC1FF6
Don't forget to delete both vendor files:
http://crackberry.com/updating-your-blackberry-different-carriers-os-make-sure-you-delete-both-vendor-files
Enjoy.