i'm not able to pay with my credits cards. there is money on so why i can't pay a song?

What do you mean by 'not accepted' ? If you are getting an error message then what does it say ?

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 - so prepaid cards will tend not to be accepted (and not all debit cards seem to still be accepted).

Prepaid cards will tend not to be accepted as they will fail the validation about being registered to the same name and address as on your iTunes account. Do you have a proper credit card that you could try, or are iTunes gift cards available in your country so that you can use them as your payment method ?

By 'mine with my name' you mean that it has your name on it and is registered to your address, the same address as on your iTunes account - and was issued by a bank in your country ? It's not an ordinary prepaid card that you can get in supermarkets ? Have you tried logging into your account, removing the card if it's still on your account, exiting the screen, and re-entering it ?

To contact iTunes Support : http://www.apple.com/support/itunes/contact/ - click on Contact iTunes Store Support on the right-hand side of the page

But if it's a debit card, not a credit card, then not all of them seem to still be accepted.