I've got to the point I only ever order anything on Amazon that's actually sold by them. I've had so many problems with marketplace sellers, even fulfilled by amazon. Total minefield.
What really, really sucks is that Amazon pools its own stock with that of the FbA sellers, meaning that a FbA marketplace seller can inadvertently or knowlingly contaminate Amazon's own inventory of an item.
This is why a year ago,
Apple sued a vendor of counterfeit accessories (like USB chargers) on Amazon -- customers were ordering from Amazon itself, paying full price and expecting genuine product, and receiving counterfeit. When Apple then ordered 100 "genuine" chargers from FbA sellers, 90% of the chargers received (!) were counterfeit. In both instances, the fake product was what FbA sellers had supplied and fed into Amazon's inventory as "genuine", and in this case, Amazon was able to identify the culpable seller, which is why Apple was able to sue it.
I wanna say that Amazon has itself stopped selling Apple USB chargers, as you cannot find them for sale from Amazon itself at all. (For example, search for "Apple 12W USB power adapter" -- there are no exact hits with Prime shipping, meaning that Amazon isn't selling it.)
Samsung has had the same issues, as I understand it.
For anything like chargers or batteries, it's better to buy directly from the manufacturer, even if it costs more. (Or buy a known-decent third party like Belkin or Anker. At least for now, those are unlikely to be victims of counterfeiting.)