Representment
The merchant's counter-move to a chargeback: evidence that the purchase was genuine, sent back through the acquirer to the card issuer.
When a customer disputes a card payment, the issuer pulls the money back straight away. The merchant then has a few weeks to answer with receipts, delivery confirmations, login records or whatever else shows the customer really did buy the thing. If the issuer accepts the evidence the money goes back. If not, the case can go to a second round (pre-arbitration) and finally to arbitration by the card network, where the loser pays a fee that often exceeds the disputed amount.
Visa's Compelling Evidence 3.0 rules from 2023 made friendly fraud easier to fight. If the merchant can show two earlier, undisputed purchases from the same device or IP address, the new one counts as the customer's own.