The right of withdrawal under European consumer law doesn't apply when you book accommodations.

If you book any additional travel services during the same visit to Booking.com, the travel service may become part of a Linked Travel Arrangement. In that case, Booking.com has, as required by EU law, protection in place to refund your payments to Booking.com for services not performed because of our insolvency. We grant this protection regardless of your booking location. Note: This does not provide a refund in the event of the insolvency of the relevant service provider. Click here for more info.