Q: HOW I DO MANAGE MY DECLINED PAYMENT METHOD

Hello ainasya,

Thanks for using the Apple Support Communities!

I understand that you are trying to add a payment method to your Apple ID, but have been unsuccessful. We know that situations with billing information can be frustrating, but we are here to help!

To begin, the following article explains a scenario where a user would be unable to add a payment method because the credit card company’s records don’t match the user’s records in the iTunes Store. I would first suggest reading over this article to make sure everything matches and is correct. 

If your credit card company's records don't match your records in the iTunes Store - Apple Support

The next article is a basic guide that gives instructions on how to change your payment method. You sound familiar with this process, but if you continue to have trouble adding a payment method, I would suggest contacting iTunes Store support as the article suggests. 

Get help

If you need help changing your payment information, credit card details, or billing information, contact iTunes Store support.

Change or remove your Apple ID payment information - Apple Support

Cheers