Pathetic Makro online service

Repeatedly I placed online orders, then my order is cancelled due to no stock but the items still show in stock on the website. I have to pay immediately while they take between 14 and 21 days to refund. This must be a ploy to take and get money, and only to return it weeks later. So is this a cashflow issue. Bad poor customer satisfaction and service. Most of my orders over the last 12 months have been delivered incomplete.