my both bank cards are declined why?

If they are debit cards then they don't seem to still be accepted in all countries, and even where they are it seems that not all work.

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 and your iTunes account are.

Do you have a credit card that you could try ?