Need help starting new account

Hi guys,
Last year my son got an old iphone 4 which had jailbreak installed.
Now he has a new phone and wants to play mpq from a new account.
I've tried deleting the game and cleaning icloud and made a new fb profile but I always end up with his old sandboxed account.
I've tried most howto's and D3 basically said "bugger off cheater" so does anybody know a way?