I mistakenly hit the enter key to make a reservation for two hotel rooms for 12/30/18. Within two minutes I told Booking.com to cancel the transaction, and they sent me a confirmation that "your booking has been canceled". They are now saying that the "cost" to cancel the mistake is the full price of the reservation -- $3,087.54. I called them this morning and they refused to credit my account, while also contending that the reservation is "canceled".