Complaint Information. Please explain your complaint: Try to be brief, but be sure to tell WHAT happened, WHEN it happened and WHERE it happened.Here's a sample to help you write a complaint letter about a product or service. Complete a simple online form to have your problem reviewed. This does not involve a legal proceeding. The more information you provide, the better we can help you. Consumer Action offers a sample complaint letter and an email complaint template. You can cut and paste these documents below. Whether you need to file a complaint, post a review, tell us about a misleading advertisement, or report a scam, you're in the right place. If you believe that you have been a victim of unfair rental practices, you can file a complaint with the Fair Housing Commission.