Booking.com Refused My Refund Despite Medical Emergency

I've made numerous reservations through Booking.com over the past five years. Unfortunately, my son fell ill one day before our last Milan holiday, and we couldn't go. Despite having a medical report in hand, we haven't received a refund for any of our expenses, including the hotel fee, hotel and city taxes, which we were charged for our stay. We also received a tragicomic response saying we should have been notified 3 days in advance. They want us to be informed of my son's illness 3 days in advance before canceling. If you're booking through this site, I wanted you to be aware of this. Thank you.