Bad online shopping experience l, online almost nothing available, but instore they say they have plenty

I honestly do not know why a groceries store have online shopping when almost everything you want to buy, is not available, but when you phone the relevant store they have more than enough stock. Online shopping is almost a must for me due to 3 small kids, Im unable to go and buy in store. But unfortunately Im forced to do so, due to no stock online. Pick a pay will also lose money because if Im forced to shop in store, I would rather pick another place. I normally order my goodies and pick it up at Fountains Mall Pick a Pay due no delivery where Im at. Im unable to buy taxan steak, 7kg potatoes, bugerbuns, hotdog buns, 30s eggs, shoulder bacon... And the list go's on, I phoned customer care they told me its a system error and will be fixed soon, still no improvement!!! I would suggest that all groceries must be made available online, if the relevant store does not have what was ordered they can swop it out or contact the customer. Is totally not a great online experience and it gets worst month after month.