Hi
Follow the instructions here, including checking that your address details fully match those on file with your card issuer / bank:
- Change or remove your Apple ID payment information - Apple Support
- Payment methods you can use in the iTunes Store, App Store, and iBooks Store - Apple Support
You may also wish to check with your bank (in case it declined Apple's payment authorisation request).
If you still need help, contact iTunes Support:
Contact - Official Apple Support
(I'm afraid that no-one here can access your account to advise why your payments have been declined. This is a user-based technical support community - you are not talking to Apple here).