I often see this kind of miscommunication from a store, it completely kills any desire to order from them again. But there is good news too. These days, a lot of shops have switched to smarter ways of helping customers choose products with product recommendation quiz where you answer a few questions and get recommendations that actually match your needs. That kind of setup really cuts down on these mix-ups with orders. If it is just a basic catalog, you might end up with situations like yours: you order one thing, something else shows up, and support is swamped.