I've been an Amazon customer (Prime members since it was first offered) and make multiple orders per week for years now. We get almost everything from Amazon including many food items. We typically only shop in B&M stores for fresh food (breads, produce, meats), bulk items (Costco), or must-have-today items. In fact we subscribe to several things that are auto-shipped to us. We're talking hundreds of orders per year.
I've had very few mishaps out of all that, probably something on the order of 0.05% or maybe even less, and Amazon has always been extremely easy to deal with. I can't think of an easier supplier, in fact. More often my returns are due to my own error, change of heart, it didn't fit, etc. and they're equally accommodating in those situations. Here in the states I don't even have to package the item up, I just take it in with the printed barcode RMA to my nearby Kohl's department store and hand it to a clerk behind they counter. They'll package it up and handle the return, and I get almost immediate credit.
I have heard in the past of Amazon going after chronic returners, those who frequently buy and return products. Costco suffers the same fate due to their extremely liberal return polices that people abuse. Which they've tightened a little over the years, but back in the day it was ridiculous -- people would buy a computer, or a set of golf clubs. use them for 3 or 4 years, then return them for full purchase price and buy something newer. So I don't really blame Amazon for giving people who meet certain return thresholds a harder time. But that's never applied to me.
Shipping mistakes happen. And scams happen, though I'd argue much less frequently with Amazon. They have some pretty tight rules on their platform, similar to eBay, which favors buyers over sellers. You can find outright scams, but they're typically short-lived. The higher risk of course is buying an item that's delivered as promised but turns out later to be junk and breaks soon after. And even then I've seen Amazon step up for the customer.
That said, I'm careful to buy from Amazon directly, or those 3rd party sellers who are fulfilled by Amazon, in which case the process is identical in terms of handling returns and refunds. I rarely buy from an Amazon seller who doesn't fulfill through Amazon, but when I do I've been fortunate so far.
The only time I've been scammed like that where a product was swapped has been from Facebook ads. Now THAT is a wildly unregulated and risky shopping platform. I once ordered a portable HD monitor from a FB ad and received a cheap (as in VERY cheap) Chinese wrist watch! I had to go through PayPal to get it refunded, but PP made me ship it back TO CHINA first and I had to fight to get the postage covered.
It's a problem every time I buy something.
And it is purchased directly FROM AMAZON.
And I had no such problems when I bought NOT FROM AMAZON!
Something doesn't smell right here. Or perhaps Amazon in Europe is run/managed completely different.