Horrible 1st time experience!!

I and other members of my family had a very terrible 1st time experience and distasteful service from Flysafair on our way back home from Dbn to JHB. We missed our flight FA/263 to JHB, while waiting at the boarding terminals, after arriving an hour early, due to a quick change in boarding gates, from A8 to A14. A decision that was solely made by the airline, minutes before boarding and departure, and then not making sure that all persons who had already checked-in were aware of this change. The officials claimed that an announcement was made but none of us heard it. How does it happen that such crucial customer information could be left to just one or two general loud speaker announcements, through rush hour terminal noise? We arrived at the boarding gate (A8) 15mins before departure time (18h30) and the ladies standing at the gate didn't even bother to inform us of the gate changes. Our names were not called out/announced, as per usual, to inform us of the new gate closing. Closer to departure time, we inquired from the roaming staff at the gate and were informed that our flight was delayed. Only after the plane had left, while still waiting at gate A8, we were surprisingly called, 1st by phone, then out on loud speakers, to come fetch our bags at the ticket sales counter. The question is, if they managed to call us out after the plane had left, why couldn't they attempt to call us out after realizing that we didn't board the flight at the new gate, and also knowing, from the system information that our bags were checked in, way before the change? Our names, or atleast one of us could have been called out to inform us of gates closing, but this was NOT DONE! The other infuriating part is that we made a free payment of a total amount of R650 (R500 by myself) for luggage. This is a kind request that we please be fully reimbursed for the luggage costs and atleast some form of refund for our flight tickets as this was utter incompetence, poor and disregard for customer service from the Flysafair staff present on the day.