FIX: Unable to update/change credit card for iCloud Storage

You may get an email from Apple that says that they are having a problem processing your credit card for iCloud Storage. The email then goes on to give you three instructions to fix this by tapping on SETTINGS -> iCLOUD then tapping on "Account" and then following on-screen instructions.

If (like me) you see that your card is OK but you are still getting the email and you cannot edit the payment details, this is what you do.

Turn off Family Sharing.

Once this is done, you will then see that the old card details are really what is trying to be used, and you can then update your payment option. This is not known about in front line support and it was only a high ranking tech support person in iTunes support who mentioned this in passing as a possible cure. Share it please as failing to get your payment option correct can result in losing your iCloud Storage Plan and placing you back at basic free levels.