Flight reservations can be canceled within 24 hours of purchase and will result in a full refund provided certain requirements are met, in accordance with Cathay Pacific's 24 hour flight cancellation policy.
You must meet all the prerequisites for a 24-hour cancellation and the refund associated with it:
You must book your flight through the Cathay Pacific website in the United States.
The flight must depart from or arrive in the United States.
When you make your reservation, your departure date is reserved at least 7 days in advance.