Booking.com unprofessional !!!!

I booked Grosvenor Private flats in Hatfield area Pretoria When I came there on the 30th May there was no booking even though booking.com confirmed nd we already made the payment! WE WERE SENT AWAY THE OWNER SAID BOOKING.COM OVERBOOKED THEM!!! No one could assist us..I've sent emails to booking.com with no response also.The owner took my banking details of Grosvenor private flats but to today I did not get my refund!! I would never use booking. Com to book anything ever again.Very unprofessional nd no one is willing to assist me to get my money back after we were driving 200 km to get to the flats they couldn't book is in! No space for us with a valid booking ..please assist Marietjie Steyn *** ..People do not use booking.com it's unreliable I had a confirmed booking!!! Nd they sent us away to look at night for another place to stay!!!!