ACCOMMODATION DID NOT EXIST

We booked this accommodation in Gloucester in February with Booking.com for our holiday in the UK in July. We arrived on the appointed date, 4th July to be told by the owner that he had no booking for us and had cancelled his listing with Booking.com 5 months earlier. Yet Booking.com paid him for our accommodation on 1st July and he accepted the payment. Booking.com says it is our responsibility to get our money back from the owner, but the owner no longer takes phone calls.