i have a new credit card number how do I change?

Please refer to Change, add, or remove Apple ID payment methods - Apple Support

My subscriptions to I Tunes and to the Washington Post used to be paid for by a VISA ending in 1304. These are no longer available to me, since I had to get a new credit card. I have my received my new VISA card, and have tried to enter that new card number to resume my subscriptions to I Tunes and Washington Post, but the new VISA number (ending in 1197) is not being accepted. Please let me know what I need to do. I have the new VISA card in my hand, and will be happy to enter the number, code, etc.

Michelle in Memphis