Bad attitude by management and No stock

I went to shoprite in nelspruit to buy the R100 subsidised special only to find one item out of the 5 was out of stock and when I enquired I was told it was really out of stock and they were told not to sell the special (by head office) which I found really unfair and asked for their manager, their manager came with a very bad attitude and told me they can't substitute the item with anything else as they will have a shortage, did not apologize or show apathy for that matter. I told her it wasn't my first time buying this special and I know it can be done. I am really annoyed that a big company like Shopright can advertise something and not have stock or an alternative for that matter or even atleast make a note on the shelf that the promo is not available. I specifically drove all the way to town to purchase the promo, a waste of my time and petrol. Please also train your managers about customer service.