I made a booking for accommodation for 2 nights (25 and 26 May 2925) via Booking

I made a booking for accommodation for 2 nights (25 and 26 May 2925) via Booking.com. So unfortunately I went for a major foot operation and the doctor told me to stay in bed until further notice. I therefore cancelled the reservation with Booking. Com. Who later said to me that the hotel needs a doctor's note. We'll the doctors note was sent to the hotel.then a day after which is 23rd May 2025, the hotel informed me that I cannot be refunded because of a short notice. Now I am wondering which short notice? Why did they ask for my docrors note? The confirmation number is 4831202189 and the pin is 9966. I could not even change the date because am not sure of my healing process. Your intervention will hightly be appreciated. Thank you.