Accommodating receptionist. Excellent location from the brisbane train station

The accomodation itself is good but I don't know what happened with the hotel booking. I already presented the e-receipt but the front desk said I still need to present my credit card and passport.. I wanted to verify my booking upon check out and ask their purpose of doing it but unfortunately no one is around since we checked out before 6am...hope they won't charge me double since I don't know the reason why they need to get my credit card...