Prices not the same as advertise

Yesterday morning about pass 7 my friend and I bought chicken ( the no name brand) @ R45.99 p/kg than at work about 1 our later we saw the exclusive deals at Pnp Wellinton & Malmesbury for R39.99 and it is also the no name brand. ( 10 piece ) The afternoon when I arrived and asked about the price difference and that I want to bye more chicken the lady said that's the only chicken left @ R45.99 p/kg. This is not the 1st time that they advertise stuff and when you get there it's not available and when you ask for a reincheck some of them have an attitude. Most of the cashiers is very nice & helpfull but the snr staff not. If the shop don't have enough stocks,etc why than advertise? Everyone of us are looking for cheaper especially now with this pandemic.