Do a print of your PRI. Look at the special services table. Entry 0 is your 011 (or international) dialing. See if it is set to delete 3 digits. If so, you are not sending the 011 to the provider. If your provider needs the 011, you need to change that entry to delete 0 vs. delete 3 under your PRI programming. If they don't want to see the 011, you need that entry to be to delete 3 digits so it strips that off.