Payment Method was Declined

See this support article:--> If your payment method is declined in the App Store or iTunes Store - Apple Support

Regards

Giulio

Here is some information on the types of payment methods accepted—>Payment methods that you can use with your Apple ID - Apple Support. If your debit card is one that should be accepted but wasn’t you need to contact the issuer, as they are the ones who rejected it. But note that not all debit cards are acceptable.