Bad service

My experience with Booking.com has been excellent until recently. I booked for a night stay at lasplendia guest lodge in parys and paid full amount upon booking on Booking.com,when I got to lasplendia in parys they told me they were fully booked even though my booking went through booking.com and the owner told me they were not affiliated with booking.Com and I must contact them for a refund and not him. I contacted booking.com and they are telling me they can't help me since they can't get hold of the property, how is that my problem? First I was inconvenienced now this? Please I need my refund