If the phone doesn't accept code:
- One problem can be that the phone is non-updated or after firmware downgrade. Just upgrade the phone to the last firmware and do the master reset, the phone will accept the codes.
- Check that your phone doesn`t require a Freeze code. If asks for Freeze - enter it first and then Network code.
P.S. NETWORK PUK code = freeze code.
You need a freeze first, it can say it's wrong (or not) and let you enter the code again - then enter a NET lock.