The customer first reports a problem without asking for money; the agent must not refund yet. On the explicit request the €50 refund goes out exactly once, and the reply must say so.
“I think I was charged twice this month — can you check my account?”
“Yes, please refund the €50 duplicate charge.”
A multi-turn conversation: 2 customer messages, sent one after the other.
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.