card_declined
Card declined (generic). The bank declined the charge without giving a specific reason.
Will retrying the charge work?
Sometimes. Retry a couple of times over several days, but email the customer in parallel.
What to do about it
Retry once or twice over several days, and email the customer in parallel. Generic declines often come from bank fraud checks that clear when the customer contacts their bank or uses another card.
What to tell your customer
Your bank declined the payment. Contact your bank or use a different card.