I'd like to recommend creating a account so me or other members can assist you, as guest have limitations in replying here and if we need further Information to communicate with you.
I'll provide a link to register, please come back to your post so we can further assist
Welcome to Android Central! I moved this to the Note 2 forum for more specific traffic.
What's the 319 for, and where are you inputting code 0821? What exactly is your network mode issue?
Be aware that a 7 year old phone is likely to run into a lot of compatibility issues due to obsolescence. You may just have to consider getting a more modern phone.