Vouchers ! , although been the only 4star or above hotel in Rudong for the last three or more years, it seems that nothing has been updated in the hotel (cleanliness is slipping the hotel is getting older and older quicker than its years) this time room temperature could not be controlled , leading to a change into a smokey room . Not only that limited English speakers mean they didn't acknowledge pre-paid status of booking as I didnt have voucher, (confirmation email, or app acknowledgement not sufficient . If there was another option (18 month away) I'd use it