Many people won't name the local dive shop that they are having, or had, trouble with. Well I say NAME THEM HERE!!! Let everyone know about the crappy service you got, the extremely overpriced products they have or the poor equipment they rented you. With any luck, they'll realize they have changes to make, prices to drop. etc...
An LDS is sometimes like a monopoly for some people. People don't always have many choices in their area, so they go to the same place, time and time again. Leaving, shaking their head and wondering how they can possibly remain in business with those prices vs. internet prices...Perhaps you'd love to complain about something, but just don't want to upset anyone because you're going to need fills!