Greenbacks not converted to Voyager miles

I have been converting my greenbacks to Voyager miles for many years without a problem. 10 days ago I phoned to convert them again and was given a reference number. After a few days I noticed that my voyager miles have not increased and phoned again only to be told that Nedbank would no longer be converting miles to SAA. Two calls later and the consultants still could not give me a reason for this situation. I requested feedback by phone or email, but still no response. I would appreciate an explanation from them, because if they no longer deal with SAA, I most certainly was never notified