Calling out a vendor for mistakes like this is not tolerated. It always ends in flame wars rather than a mature discussion. General rule for B/S is whatever transaction it is, it is best left between the buyer and seller in PMs, not public forums.
The point of marketplace feedback is because vendors and sellers wish to have such feature in place as part of their promotional strategies. Whether the feedback is positive or negative, you learn something in every feedback shelled out. Negative feedbacks, though it may ruin the reputation of another, nevertheless can effectively help the vendor improve his sale activities further. If the vendor receives negative feedback for a bad transaction, then he deserves it and has no right to complain but we should not call him out in public per the B/S rules.