Payment method declined due to pending app

Today for the first time after years i have experienced my payment method being declined and as a result i am unable to update or download free apps. From what i understand this is happening because of a pending in app purchase. My question is, will the pending purchase be automatically paid after funds are added to the card that was used at time of purchase even though the payment method was declined? Also, is said card not ''valid'' simply because there are no funds to pay off the pending purchase? Thanks in advance for your insight on the matter.