Book now pay later is a scam.Booking.com

We booked a hotel in London for September. The booking was made in April and paid in full - booking.com said it was guaranteed. Until last week when we got an email saying our booking was cancelled as the hotel would be closed. I checked booking.com and it was still accepting reservations for the same hotel, same room type, same dates. More expensive now, though. I called to query why my reservation was cancelled and they said the hotel had overbooked so some reservations were being cancelled. No apology, no compensation and we are out in the cold and looking for new accommodation. Shame on you, booking.com!