linking in a new xbox account to an exisiting EA account

My son decided that he wanted to play the Battlefield Games with myself so he linked in his Xbox live account to some made up nonsense and as a result he cannot play any Battlefield games with myself as I tried to set up an EA account for him, I then tried to link in his Xbox account with his EA account and that's when I found out that he has wrecked the link.

Is there anyway that EA can sort out the links to his Gamertag so that he can get a refreshed link so he can play Battlefield with his dear old dad.