I don't agree with this as they shouldn't be able to raise the price on you for not showing up, but here is what their policy says

Hyatt Gold Passport award reservations are subject to the cancellation policy of the individual property at which member is redeeming an award. If member does not follow proper hotel cancellation policy or if member does not check into the hotel, the credit card provided with the reservation will be charged in accordance with the hotel’s cancellation or no-show policy. These policies vary by hotel and each hotel’s cancellation policy can be found on the hotel’s website on hyatt.com, by calling the hotel directly, or by contacting the local Worldwide Reservation Center.