I have a history log of this number on my phone going back to the 29th January 2016. This number phoned me 13 times this year. It started in December some time, I don't have a log for last year. This must be some kind of automatic robotic call maybe connected with MTN, because that is my carrier. I am also from South Africa. Would like someone to talk to who experience the same thing. Maybe we can investigate this, just for fun.