Tablet 4 Months Out of Stock

I am waiting for a Samsung Galaxy Tab S3 since October 2017. I visited both MTN stores in Centurion Mall at various occasions and put my name on a waiting list. All MTN stores that I asked informed me that there is no stock and they wait for the warehouse. How can it take more than 4 months to get a popular tablet? Also, no communication from the stores. This specific tablet is advertised in the monthly catalogues, but no stock when queried. Please advise on the stock situation as my original intention was to have it for Christmas 2017.