Yes, most hotel reservations are fully refundable provided that you cancel prior to the hotel's cancellation deadline, which often is within 24-48 hours of your arrival date. If you booked a non-refundable reservation, you might be able to still cancel and be given a refund within 24 hours of booking. Plug in your dates, click on "Search", then use the filter option "fully refundable" to review the best deals available near General San Martin Square.