Flight cancelled with no notification

I am a gold status voyager members and have spent about R200 000 on flights for 2015 alone. Using my miles I booked a flight for my girlfriend from jhb to mozambig departing on the 25th of December and returning on the 30th of December 2015. I paid about R1200 in airport taxes. As I received my booking confirmation I realized that I had made a mistake on the return date and booked the 31st instead. I immediately called the SAA office to asked that the return date be changed. Even though I called within 5 minutes of making the booking I was charged R1750 to make a chance. I was obviously not happy with this rediculous charge so I decided to email SAA to complain. Nobody even bothered to reply to my email. Being such a loyal customer and having spent so much money on flights I thought that I deserved better. Today the flight was scheduled to leave jhb at 9:35 am. My girlfriend arrived at the airport early to check in to the flight and was told the the flight had been cancelled and than now she would be on the 14:00 flight. No email was sent to notify us of the change , no phone call was received. 6KRQT8. Will never usa SAA again ! To do this on xmas.. shame on you SAA !