Explain the problem. 1. Contact the company's customer service or escalation department. 2.Use consumer protection websites or forums. 3. Find information and tools to submit a consumer complaint to the Consumer Financial Protection Bureau. Consumer Action offers a sample complaint letter and an email complaint template. You can cut and paste these documents below. Learn more what a complaint letter is and how to write one, including tips, a template and an example you can use for guidance. Be clear and concise. Describe the item or service you bought and the problem. If you are considering filing a complaint against a California company, this article focuses on five main strategies to assist you with filing a complaint.