Call back on Monday and demand to talk to the room manager. Don't take no for an answer if you're globalist. Threaten to take your business elsewhere and write a bad review about the hotel if they don't let you book a room. I just checked my secret Hyatt inventory software and this hotel still has plenty of rooms. They are hiding availability right now to jack the price up the day of since they can predict the weather and know that some people are going to be delayed overnight and need the room. Report them to the attorney general of your state. Don't give up!