i can't change the credit card details
the expiration date of my credit card is changed, but I can't change it in modify.
Question marked as
What happens when you try? Error message(s)?
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 necessary, contact iTunes Support for assistance. See the Apple Support articles below for contact information.
Apple Support schedule phone call
Starting an online chat with Apple Support
If necessary, try Twitter
https://twitter.com/AppleSupport. People have posted it may take an hour or more to get a response.