Staff seem to be unaware of how to respond to situations

On 28 July 2018 I went to the Vincent Park branch in East London. There was a great special on stock (2 x 24 pack for R 30). I wanted 2 chicken flavours but unfortunately there was only 1 chicken. I was told by Desmond that I can take another flavour and just swap it when I come again. I went to Pick 'n Pay yesterday (6 August) and still no stock - understandable because of the fantastic bargain. But what really bothered me was that when I told the supervisor that there was no stock, she didn't know what to do. So eventually she asked me what I wanted to do. I had to ask if she couldn't take my details and let me know when the stock does arrive. Disappointed that staff don't know how to deal with such a problem. I'm also concerned that I'm not going to get any feedback if I just leave it there because my name and contact number was just written on a s**** piece of paper. Couldn't Pick 'n Pay have a book (similar to their official raincheck books and refund books) where customers can leave their details and what product (that isn't on promotion) they looking for? I can't imagine that I'm the only customer that is looking for products that are out of stock.