One time I had an order that was apparently lost, so I clicked on 'leave seller feedback' and left a comment about the (nonexistent) delivery process. It ended up getting a comment 'this is not feedback about the seller, it's for the delivery service' but all of a sudden my product was found, and delivered the next day.
Keep in mind that this could be a coincidence, and that I can't say for sure if my 'feedback' lit a fire under anybody.