Flight changes without notification

My wife and I booked flights in March 2015 for 3rd July 2015 and flight time was advertised at 17h05. When we checked on the day of travelling, the flight time had been changed to 18h15 without any notice given to us. We contacted Mango were told its within their rights to change flight times. We went to the airport early to try and get a standby onto an earlier flight, they tried to help but wanted to charge us R370 per person to get the flight. After insisting we wont pay the put us on standby. We made the standby flight but that was delayed so we ended up leaving after 18h00. Their excuse was that the Dbn July was on. I don't care about any horse race. Net result was we were late for a family commitment and by then we shouldn't have even bothered to go. <br> <br> They sent me 2 vouchers for R250 to use on the next flight but that means we still have to spend money with this hopeless lot. After giving us the run around, poor service, no information on changed flights the very least Mango should do is give my wife and I a return ticket each!