Pick n pay asap Westonaria is a nightmare

Pick n pay asap Westonaria is a nightmare . Can someone from pick n pay please explain why they allow us to add things to cart and even check out ,pay and then 30min get told the product is out of stock ? How does 1 wait for an order and get canceled 30 min after waiting ...if that's not enough ,u order then not get all the products u paid for because they were available on the App .. We believed the asap app was introduced to make our lives easy but it seems its just making things worse.