DONT BOOK THROUGH BOOKING.COM

I HAVE TRIED 48 hours in advance to contact them through chat, Facebook, email, phone line and the airline but no assistance to change my flight !!! I’m about to lose my money because the flight is on the 2nd of August. I do not know what to do going forward as I’ve exhausted my options and they keep making promises but no help at all !!! I’ve got proof of all of this !!!