払い戻す
はらいもどす · haraimodosu · JLPT N2 · verb-godan
to pay back
💰 払い戻す = 払い (pay) + 戻す (send back): pay, then send the money back = repay
戻す means to return something to its original place or owner. Adding 払い (payment) gives money paid out and returned, which is why it also means a refund.