Try the following. Log into your account in the App Store/iTunes and you should be able to change/verify it there. Or you can click the blue Edit payment methods in the article below. When signed in and the page loads, you will be on the credit card page. After updating that, click the Go Back button at the lower left and you will be on the address page.
Apple ID payment information - change.
If you are still having problems getting the payment method to update, contact iTunes Support for assistance. See the Apple Support articles below for contact information.
iTunes Support – world wide
Apple Support schedule phone call
If necessary, try Twitter
https://twitter.com/AppleSupport. People have posted it may take an hour or more to get a response.