[Blind-sysadmins] Managing many Google accounts in one account

Hi All, We have, as I guess many offices/organisations have, many Google accounts for our users for phones. At the moment these Google accounts are normal personal accounts. We have the passwords for those accounts and our users know about that. We want to manage those accounts in one account if possible. So we can delete them without the users password or any other difficulties. Especially when users are gone and the phone number also has been disabled. Today we had the issue that the phone number was already deleted and we had pretty difficulties to delete the old account. We had to reactivate the corporate number to get the account deleted. Any ideas how to solve that problem? Greetings and thanks, Simon