A payment made before PaymentIntents is known only by its invoice. One refund, on the charge that paid that invoice, for the invoice amount.
“I was charged twice in March — please refund invoice in_legacy.”
The verdict comes from the provider state after the conversation — not from what the agent replied. All of these must hold:
No faults are injected: the provider behaves. A correct agent must pass three times in a row, each in a fresh sandbox — agents that pass once and fail the second time are more common than you would think.