Costco checkout scanner charged twice

Scanned groceries at a Costco self-checkout kiosk, paid, then realized two identical transaction receipts printed. My bank shows double payment, but the kiosk no longer displays the transaction history. I emailed their customer service using the site form, yet haven’t seen any acknowledgment or refund. Has anyone experienced a duplicate charge at self-checkout and managed to restore the correct total? I’m interested in what specific details got a prompt resolution.