Makro online orders - big failure

Receive regular reminders of online specials from Makro South Africa. I required some Castrol engine oil. The required item and quantity was selected and only after selecting the delivery process was there a warning "No stock". Surely the system should indicate the "no Stock" status before you proceed with the order. I have completed an online complaint, but doubt whether I will receive a reply.. Stay away from Makro online orders. They had massive problems with Black Friday orders, some only delivered after December 2019. There was a massive social media outcry due to late or no delivery. The only safe way to purchase goods - go to the store.