card declined on app store

If it's a debit card that might be why, not all seem to still work with iTunes, and they might no longer be accepted at all in some countries. Do you have a different card that you could try ?

For a card to have a chance of being accepted it needs to be registered to the same name and address (including format and spacing etc) that you have on your iTunes account, and have been issued by a bank in the country where you are (and therefore the country which is on your iTunes account).

They are registered to exactly the same name and address as on your iTunes account ? But as they are debit cards you might not be able to use them with iTunes

They might belong to you, but is the name and address on your iTunes account exactly the same (including layout, formatting, abbreviations) as the cards are registered to ? If they are, and you are still getting the declined message, you won't be able to use them with iTunes (unless it's the card issuers that are declining them for use with iTunes)