Can’t update/remove/change iTunes payment method

I managed to get some Apple support on this. You need to log in via this web site https://appleid.apple.com/#!&page=signin

Once here it is possible to update the expiry date and other details of the credit cards you have on file. It solved my problem

Having same issue, where it says I need to update the payment method in iTunes and AppStore, but won't let me edit the card expiry info.

When I try to update OS software, I get the same "payment method expired" message, but it goes to a window where I *can* edit the expiry date... but after clicking "Done" it apparently doesn't connect go through, as I continue to get a "payment method has expired" message that loops me back to the same window where my expiry date did not change.

Unable to add new payment method as a work-around. Says I need to update the current card expiry date, but there is no apparent way to do so.

Change, add, or remove Apple ID payment methods - Apple Support

If you can't add cards to Wallet for Apple Pay - Apple Support

Payment methods that you can use with your Apple ID - Apple Support

The situation occurs for me too because the card is expired and it is the only card on my account. When I try to add a new card I am told to verify the existing card before adding a new one. I cannot verify the existing card because I'm given no option to update the details other than the CVV. So the existing card entry remains unverified. So I tried to remove it. That actions wasn't permitted as I have a family account and iTunes will not let me remove the only card on my account.

NICE, RESOLVED! thanks Crezzas - - this totally worked going through appleid.apple.com to update payment info while unable to do so through iTunes.

In case this is helpful for other users, I had to do a few extra steps to fully resolve: I found that after updating my card info in appleid.apple.com, my iTunes account info listed the new card but when I clicked on Manage Payments it still showed the old card, along with the same issue of not being able to remove or edit this old card. However when I tried to download an app, I was asked to verify my payment method, and now it had updated the card number to the new one and I was able to verify successfully, and the old one was replaced by the new, correct one in my details.