No promo line available at different stores

We were looking for a tablet for my granddaughter as we are leaving for holiday on Thursday. I went online and came across a, what I found a brilliant product at a very good price as my granddaughter has been saving up for the last year and we wanted to surprise her but also make her feel that saving is a good thing as you are then able to buy things that you like. I saw this tablet at Ackermans being advertised for R599.00. My wife and I immediately went to the branch at Mall@Carnival where we were told they don't have stock. We drove to the branch in Brakpan and were told they haven't received any stock as yet. I phoned the Springs and Eastgate branches and same story , sorry we don't have stock and will let you know when we get stock. This is ridiculous as how can all the branches not have stock ???