According to ANA Cancellation Policy If ANA cancels your flight and the alternative flight offered to you is not suitable for you, you can choose to fly the alternative flight for free or cancel your flight and request a refund.

There is no cancellation fee for booking tickets for children under 12 years of age. The 24-hour cancellation policy applies to all classes of tickets, but not to reward tickets. Refunds for ANA flight cancellations will be processed within 20 business days of the cancellation date.