Two conditions have to both be true: the payment must already show status Paid out, and at least 7 calendar days must have passed since its charge date. That 7-day figure is a GoCardless-side "safer refund" hold, not something the plugin adds on top — it exists as a fraud-protection measure on their end, and there's no setting to shorten it. The Refund button simply doesn't render until both conditions hold; there's no error message to catch because the option isn't offered until then.