Qatar Airlines — seat booking incompetence and poor customer service

I booked my specific seats on 20 September 2017 to ensure that my Family could be accomodated together in an area of their preference, for our Flights to Phuket on 8 May 2018. At time of booking I recieved confirmation which I printed and kept. When I checked Flights and Seat Reservations yesterday 30 April 2018 I discovered that all of my outbound Seat reservations had been re allocated to other Passengers. I called Qatar Customer Service in Johannesburg and spoke to Vincent Motshegwa. He first tried to convince us that we had chosen the wrong seats in the first place and then became agressive when I was not satisfied with this approach. I informed him that I would forward proof of booking to him to enable Qatar to rectify their mistake. He has still not given me feedback on my request.