Unexplainable Bad Service - Reservation no :MNNQVH

I made a booking for a return flight for my 59 year old mother and brother between EL and OR Tambo Int. Upon return from OR Tambo on Flight 242 scheduled for departure at OR Tambo at 18h:30 on 07-Dec'15 . The flight was checked in online and printed emailed boarding passes for both travellers (copy of email available). Arriving at the airport just after 18h:00, they were advised to go back to the check-in counters and re-print the boarding passes. The security at the gates even asked my mother to remain behind and for my brother to run and ask to re-print the boarding passes. Not only that he was made to start the queue from the back and when he got to the counter he was sent from one person to the other and eventually assisted by the third person. The two boarding passes were indeed printed and went straight to the boarding gates. However, upon their arrival at the boarding gate they were told that boarding has completed, thus missed the flight. <br> <br> Question: Firstly, why emailed boarding passes did not work. Assume they were late, why re-printed boarding pass and upon re-printing the boarding passes why message was not sent to boarding gates, names called at the airport speaker?