Our customer used his bank-issued Mastercard debit card in person to pay for a hotel room. The hotel employee told him the transaction was declined so he paid for the room in cash. The debit card was not declined. When the customer saw the charge on his account he called the hotel to request a refund. The hotel is insisting that the transaction was not completed and that they have no record of it. Our customer is now asking us to handle the dispute. I don't believe Reg E applies as the customer initially authorized the charge. We are unable to submit a chargeback through our processor as the card was present. What else can we do or should we do or are we obligated to do for our customer at this point? Any help is appreciated.

While you do not have chargeback rights for fraud related chargebacks for card present transactions, there is no such restriction on filing a chargeback for a "Point of Interaction Error" Chargeback code 4834.

Since the customer authorized the charge, I agree that there is no Reg E protections, but our contract with Mastercard does require that we attempt to assist the cardholder to protect the brand integrity.

In order to have chargeback rights Mastercard will require:
A cardholder letter, email, message or completed Dispute Resolution Form-Point-ofInteraction (POI) Errors (Form 1240) describing the cardholder’s complaint in sufficient
detail to enable all parties to understand the dispute.
The cardholder letter, email, message or completed Dispute Resolution Form-Point-of Interaction (POI) Errors (Form 1240) must specify the alternate means of payment providing sufficient transaction details to allow the merchant to locate the alternate payment.
When a non-Mastercard method of payment was used, documentation detailing the payment by other means. Examples include, but are not limited to:
• A bank statement documenting payment to the merchant
• A canceled check
• A receipt showing cash as the payment method

Thank you so much Brian!