Are the actions of Amazon any different from what Walmart has done in the past? Just about all you describe, Walmart has been doing for 20+ years (probably closer to 30)
People have also been saying Walmart is quite anti-competitive for years for what that's worth too.
No? When exactly did they start selling large numbers of items on their website that aren't in stores?
Hell, Frito even has their own employees stock the shelves, which is why the chip aisle tends to look immaculate compared to the rest of the store.
Something sounds odd, because I interviewed with a no-name company that handles this sort of thing close to a decade ago, and while I don't remember if they did it for Walmart, they provided similar fulfillment services for several large e-commerce websites.