Every complaint is important to us. Here's a sample to help you write a complaint letter about a product or service.To file a complaint against a company with poor customer service, you can: 1. Contact the company's customer service or escalation department. The best way is to write a full report - as much as you like, all details, all your feelings, rants, complaints, personal criticisms of the service-people. A statement of damages form must be completed and you must purchase a summons from the court for each defendant to be served. Provide the complete and accurate name, address, and phone number(s) of the company or individual(s) with whom you are having a dispute. A sample complaint to commence a civil action in Massachusetts Superior Court. Step 2: Fill out and file the proper forms and pay the fee. The preferred method for submitting a concern is through our online submission form as it allows for more direct, timely receipt and review of your concerns.