I have never waited 40 minutes to just check into a room that I have pre-booked in my life and I travel quite often. Customer service-wise, if you have a line of people just wanting to simply check-in (no changes) which takes less than 5 minutes per person vs a large group that has a declined card, wanting to switch rooms around, have specific wants and needs, hotel maintenance issues, etc, etc… you should politely ask the group to let you help the remaining customers who have been waiting for an abnormal amount of time, and then proceed to continue on with the group so everyone remains happy and has a good first impression. We will stay elsewhere next time with all the options in close proximity.