First, choose the consumer complaint form that fits your problem. Here's a sample to help you write a complaint letter about a product or service.Feel free to call our consumer assistance line at (919) 716-6000 should you need help completing the form. Before You File a Complaint. You may wish to file a consumer complaint with the North Carolina Consumer Protection Division. You may file a formal complaint with the North Carolina Utilities Commission. Individuals may file formal complaints without an attorney if they so choose. Complaint Hotline: 1-800-624-3004 (within NC) or 919-855-4500. Read below the letter to find out why the highlighted words are incorrectly written, which will help you to avoid common mistakes. Consumer Action offers a sample complaint letter and an email complaint template.