About payment.

Check your default payment:

Sign in to your Apple ID account page and edit / update your Apple ID details.

https://appleid.apple.com                                                     

On the Sidebar click Payment methods -> then tap Payments Methods and tap Manage payment method.

Or -> Add a payment method to your Apple ID

Add a payment method to your Apple ID – Apple Support (UK)

• If you want to change your card, add first the new card, then remove the old one.
• or if you use your Apple ID balance, you need to set your Apple ID balance as your default payment.

If you update your payment method or add funds to your Apple ID balance, It would take about 1 to 3 business days in order to process.

If you're still unable to update your payment method, Contact Apple Support.

My payments was declined and I have money in my accounts. I do not understand why.

If your payment method is declined in the App Store or iTunes Store, see -> 

If your payment method is declined in the App Store or iTunes Store - Apple Support

Scroll to:

• How to complete your purchase if a payment failed or was declined
• If you still can't make a purchase
• Still need help? Contact Apple Support.

I do not understand why.

We don't know why. No one here has access to your account.

We are also users of Apple products & services like you.

Hello ~ What happens when you try? Messages? Any help by clicking on this Apple link?

If your payment method is declined in the App Store or iTunes Store - Apple Support

~Katana-San~

Hello ~ Good work and enjoy!

~Katana-San~