How do I get rid of old disabled username? I can't update Apps as keeps asking me to enter password of an old disabled username even though phone now set to different current active username.

iPhone 5c, iPhone 6 & iPadMini iOS 8.4. How do I get rid of old disabled username? I can't update Apps as keeps asking me to enter password of an old disabled username even though phone now set to different current active username. When I try to update Apps I get the 'Sign In to iTunes Store Enter the Apple ID password for "xxx".' message - though this is an old username disabled by Apple and not the one listed in my phone settings. I enter what might be the old password for that account (disabled x years so not sure) and it then gives me the following message: "Your account is disabled. This Apple ID has been disabled for security reasons. Tap Reset to reset your account." Then it goes to 'Password Retrieval' -which gets me nowhere because if I ask it to reset by email, no email arrives (likely as account disabled...) and same with going through answer security questions. So I am in this interminable loop. Can anyone help??