Airbnb writes on their help page that you can contact them in case a cancellation has been made under extenuating circumstances. In order to remove the cancelation penalties, they ask you to contact them, yet they provide no way of doing so. They provide no contact information. I've searced through all the menu items, there is no option to contact airbnb after the reservation has been cancelled. Also, every email written to airbnb simply gets returned with an infuriating "sorry! email not received". Maddening.
The below is from the help pages. They don't provide any contact info!:
"Claims can only be considered after a reservation has been canceled. Once you have informed your host or guest and canceled a reservation, if you feel that your reason for cancellation is covered by Airbnb’s Extenuating Circumstances Policy, contact Airbnb for consideration."