Keep trying throughout the year, as space may open up. The permit system does not allow for cancellations or refunds, but it does allow patrons to sell back their permits to others via the Havasupai permit online platform. The dates, duration, and number of people in the party must remain the same in order to make the exchange. Alternatively, you can request the exact dates you'd like and the system will automatically book and charge you if those dates become available.