Booking.com - Overbooking of property

Booking.com south africa is a ****. For the long weekend 8 to 11 Aigust 2019 I booked a property in marloth park received instant confirmation and my credit card was charged R4235. 28. I had to contact the property owner to find out where the keys need to be collected. I was informed that the property was alteady booked by someone else and that i cant stay there. So far i have co tacted the property owner as well as booking.com numerous times to refund me my R4235. 28 and no replies. At this stage i wonder with how many other people this is being done to and how many other people have been ****med this way.