It is not possible to move Battle.net Balance between accounts.
It is not possible to move a Call of Duty account to another Battle.net account
Information on where to update your Activsion Account Email
Information about consolidating Battle.net accounts, and how to play on multiple Battle.net accounts at the same time.
How to attach an Authenticator to your Battle.net account
How to see if your Microsoft Account and Battle.net Account have been correctly linked for Game Pass
Troubleshooting steps for issues while linking a PlayStation Network, Xbox Live or Nintendo Switch account to a Battle.net account
Information about removing an authenticator you did not attach
What to do if a friend or family member has access to your account and has updated the account details, are preventing you from accessing the account, or has taken gold or items