How can I update billing information for the non-managing account in a family sharing group? This morning I tried to download an app off of the app store, and it asked me to verify the billing information for the master account. I am in college, and share downloads with my family. The app store wanted the security code for the card on the account. This was an old card, and my father switched cards this morning in the billing information. I have restarted the app store and my computer, but the old card number still appears in the billing verification window in an un-editable field. 



He does not remember the old security code. I also tried looking at the billing information through iTunes, and the account page keeps failing to load despite a strong internet connection. How do I edit the billing information?

Update: Account information loaded after 15 minutes in plain HTML:



Signing in and out of the account did nothing. I clicked Manage in System Preferences, and navigated to the family settings. There was no area to view, let alone edit the billing information:
The billing information was not updating on my end because it was not entered correctly on the parent account. Errors in the expiration date of a card or the security code make it seem as though a new card is in use on the parent account, as the new card number will show up. Security information will need to be verified on the parent account before any family accounts can make purchases.