clipped from www.blogherald.com

First, you introduce or identify yourself. This would help put your complaint in context. You don’t have to explicitly state your real identity, particularly with anonymous blogs, for instance. The important thing is you establish why you are being negatively affected by the product, service, or persons you are griping about.

Next, share some specifics about that thing you’re griping about. You can’t just say Acme is a stupid company that sells stupid products.

Next, propose a solution or a compromise. Instead of just shouting out for your money to be returned, or for the people responsible for the product or service to fix things, do propose a constructive solution.

Get in touch. Most of these complaints would perhaps be best addressed directly to whoever it is you are feeling bad about–whether through email or talking to someone who can help you. I would usually only blog about a bad experience if there were no other recourse, and so I can warn other potential users or customers.