Missed Flight, Had to book new tickets, Unhappy

I booked flights to Cape Town on 15/08/2015 departing 03 December 06:45 AM (R1200 for 2 adults). On the morning of 03/12/2015 we got to Lanseria Airport at 06:10 and were told that we missed our flight and it has already left for Cape Town and that we had to go to Customer Enquiries. We stood in the queue for 15 minutes and was assisted at 06:28. We were told that we did not adhere to the T's and C's as it stipulates that we need be there 40 minutes prior to our flight and we were there 35 minutes prior to our flight. We received no communication from Mango informing us that our flight time was changed to fly earlier. We were then told it would be cheaper to book new flights that to change our missed flight for later that day which would have cost us an additional R3200. We had to book new flights which cost us R2800 departing from O.R Tambo. We lost R2800 due to Mango's negligence. When we got to O.R Tambo we met a lady flying with Safair and pitched up at Lanseria (Wrong Airport) Safair changed their time so they can get to O.R Tambo without charging them additional air fare fees and penalties. Mango didn't inform me of the change, SO I WANT MY R2800 REFUNDED. Reference MVRPVR