+1 for 1Password. It’s awesome.
Also: yes, contact the developer. we always get a few honest folks that get accidentally blocked by overzealous credit-card security. It just takes about 10 seconds to unblock them – then they can try again.
And to answer your question directly: is there a “global website” for stacks? No. Each vendor is independent – however, like all online businesses, we all collect money through PayPal, Stripe, and the credit card companies. Those large payment processors are global and do maintain their own lists of declined cards.
But assuming your card (or PayPal account) is valid, then it’s usually just the vendor’s web store that puts a short-term block on too-many repeated attempts to enter CC info. And that’s usually easy to rectify.