I had a very similar experience last month. I ordered this toaster[1]. When I received it I noticed that in their user manual they were offering a "gift" in return for an Amazon review. Although to be fair they didn't explicitly demand that the review had to be positive. I submitted this 4-star review [2] to Amazon: I received the toaster not too long ago. It looks just like in the advertised pictures and works fine.…
The thing you have to know about Amazon is that they combine all the reviews for all sellers of the same product (to the extent that Amazon thinks it is the same product). As such, reviews aren't an appropriate place to leave feedback about a seller, and leaving your review up would have been misleading. The reviews are only supposed to be about the product. You can leave feedback for sellers by clicking on their nam…
That said, there was one review I found helpful because the review said it (something physically large) was damaged in shipment even though they returned it twice.
Maybe there should be a workflow for "You are purchasing from 81% positive - would you like to see their reviews as a seller?"