Worse online booking site

I am furious with the way in which bookings.com handle my dispute. I used the app and booked accommodation and paid online. I get to the place and they notify me that they haven't received and email with proof of payment. I was told to pay cash and booking.com will refund me. This hasn't been the case and they say I didn't contact them to help when I didn't and haven't received a response to date.