POOR STOCK CONTROL AND BAD SERVICE

I have been trying to upgrade my one cellphone contract for the past 4 weeks now. The device a want to upgrade to is the SAMSUNG GALAXY A7 TAB 10.4" tablet. It was advertised in the December Yello Trader for as R299 for the 12 gig package. I tried the Bluff Dbn store, Paviliob Dbn store and MTN Sales no stock. I now looked in the Jan Yello Trader and the sam device is R389 for the same package and there is still no stock. Why advertise devices you never have stock of