I can't use my account balance to purchase devices in the Apple Store

Apple may require the presence of a payment method such as a credit card even if you are buying something with account balance. In your case the financial institution is the card issuer.

This document explains how to add Apple ID payment methods on an Apple mobile device, a Mac, or a PC; click here --> Add a payment method to your Apple ID - Apple Support

If an item appears in red then it is no longer working and you either need to replace it or get it working again.

To find out how to remove a payment method, or if you can't remove your last payment method or use no payment method with your Apple ID, read this article --> Remove a payment method from your Apple ID - Apple Support

- If you are updating an old card and have ongoing subscriptions, or are a Family Sharing Organizer, you may need to first add the new card and make it the primary payment method before deleting the old card.

Review this document about what to do "If your payment method is declined in the App Store or iTunes Store" Click here --> If your payment method is declined in the App Store or iTunes Store - Apple Support It mostly just suggests you make sure your payment method is up to date or to try a different one. Apple is just checking with the system linking to your financial institution and asking if the payment method is valid. The system is providing a negative response. Make sure the name and address are entered exactly as it appears on your financial institution bills and that the 3 digit CVV is correct. Check with your financial institution about the status of your card.

Make sure this is one of the payment methods that you can use with your Apple ID; click here --> Payment methods that you can use with your Apple ID - Apple Support A solution may be to use a method from the same country as the store you are using, but Apple no longer states either way if this is a requirement (it used to say, "Make sure that the billing address for your payment method matches the billing address for your Apple ID" but has now dowsized this to "You might need to ask your financial institution to allow international purchases on your debit or credit card." in: If your payment method is declined in the App Store or iTunes Store - Apple Support .)

・Unfortunately the list is somewhat general and does not list individual brands of cards (I guess there are too many and are constantly changing).

・Also read any footnotes in the document.

・Finally, note that the document only says which methods _are_ acceptable, not which ones _must_ also be present under certain situations such as when a subscription is involved.

If you still have problems, contact official Apple Support. Click here --> Choose your country or region - Official Apple Support Select your country, then a product. If you don't see one that handles your issue then keep experimenting with selections until you reach one that gets you a chat session or a telephone call and get the representative to redirect you.

or:

See a list of Apple phone numbers around the world, in this article --> Contact Apple for support and service - Apple Support

If you're in India, click on this link to read an April 2022 notice 'About billing for Apple subscriptions and media products in India' --> About billing for Apple subscriptions and media products in India - Apple Support

Additional verification that may be required when making purchases in Europe --> About billing and purchases in Europe - Apple Support