Booking.com is horrific!

I booked a car rental. Got to the rental company and we discovered my driving license had expired. They could not give me the rental car. When I phoned the car rental company on the Monday they agreed to refund me in full. We then discovered I had done the booking through Booking.com and they said I would have to deal with them. They only want to give me a partial refund. ZAR 1481.91. I paid the full amount of ZAR 3,704.77 Its disgusting to rip customers off like this