The whole purpose to sending a confirmation is so that you can check and correct it if there are any errors. Fixing errors is part of the hotel business. They represent themselves as a competent hotel chain providing quality services to business people. Responsible and reliable businesses handle and correct mistakes, instead of looking at them as an opportunity to scam their customers.
If you had wanted to gamble, you would have played the lottery, not booked a hotel reservation.
You corrected the error immediately when you found it, and in fact still booked your correct reservation thru them. Dispute the erroneous transaction thru your credit card company, and file complaints with both AAA and BBB.
If they argue "contract", you argue "disclosure", and "confusing and misleading". If they are going to market with predatory practices, you nail them on their failure to disclose their predatory practices.