Changing flights - NWHZJH

I booked flights from King Shaka to OR Tambo to depart 6:00 on 20-5-2015.<br> <br> I was informed that my meeting in Pretoria was cancelled (19-5-2015 @ 21:00) and immediately tried to change the flights however the contact centre closes at 21:00 till 7:00.<br> I tried to do this on the web also without any luck. No changes can be made on the web and it also says that if you do changes it must be 2 hours before your departure. How can this work. The centre opens at 7 but my flight was supposed to be at 6:00. How can you do changes if the contact centre was closed.<br> <br> Bid-vest Car Rentals and my other bookings was changed or cancelled without any hassle.<br> Kulula, this is not your fault that my meeting was cancelled because of an accident and I had to change my booking but surely you should be able to be reached. The airport is 60km from my house but even If I drove to the airport they would't have been able to help as the Information desk was also closed. I tried to phone them from 4:30 this morning.