Where else can I post a review of an online business?

I got screwed (out of $6.50 for shipping and handling and my sense of decency) by an out-of-state business that failed by 21 days to deliver an item within their professed delivery window. (Not to mention that they didn’t even mail it until I inquired about the status of my undelivered order.) I filed a complaint with the company’s local BBB and also wrote a factual, negative review on StumbleUpon. Is there any other mainstream business or URL review site where I can post a review or comment? I am aware that I could give it a rest, but I’m feeling the need to prove a point.