Changing credit card details
I have just cancelled my credit card linked to my Apple ID. How do I change to another credit card?
MacBook Pro 13", macOS 10.13
Apple ID payment information - change
If you have problems, contact iTunes Support. Either use the form or scroll to the bottom of the page in the 2nd link. Follow through the screens to get a chat or telephone option. You may need to pick a problem that is slightly different than yours to get a chat option.