Cant download apps because payment information won't update the expiration date

Apple is a goober. So if you can't download an app from the app store make sure your account is verified and payment information is up to date.

If it keeps defaulting your date back to the current month and year you are in this post should help. Unfortunately the only way I have found to fix this problem is going on my old Mac book and changing may payment information on there make sure accounts are synced hope this helps.