Q: Why itunes doesn't accept my payment card

If you are trying to use debit cards then I don't think that they are still accepted as a valid payment method - they are not listed on this page and there have been a number of posts recently about them being declined. Do you have a credit card that you could use instead ? Credit cards are generally considered safer than debit cards.

If you only have debit cards then you can try contacting iTunes support and see if they can help, but I don't think that you will be able to use them : http://www.apple.com/support/itunes/contact/ - click on Contact iTunes Store Support on the right-hand side of the page

Try registering a credit card instead of a debit card. It would work.