How do I challenge a Booking.com accommodation refund dispute?

Booking.com is a booking platform, not the accommodation provider, so the first thing to work out is who holds your money and whose policy is being applied. The property sets the cancellation policy you booked under, but Booking.com is still responsible for its own conduct under the Australian Consumer Law, including how the listing was described, how a cancellation was processed, and any charge it took directly.

Check the exact policy on your booking confirmation before you argue. If you cancelled inside a free cancellation window, or the property cancelled on you, or the room was materially not as described, you have a concrete basis to demand your money back rather than accept a credit or voucher. Keep the confirmation email showing the policy, the cancellation screen or message with its date, your payment record, and every reply from the property and Booking.com customer service.

If Booking.com and the property both stonewall, you have two escalation paths. A chargeback through your bank or card issuer is often the fastest remedy where the charge breached the cancellation terms you booked under, and chargebacks are time-limited, so do not sit on it. For the consumer-law side, the ACCC and your state fair trading body deal with misleading listings and unfair conduct by the platform itself.