Be polite and reasonable in your letter. The person who will read it probably didn't cause the problem, but may be very helpful in resolving it.If you are going to submit a complaint form to us, please make sure to include COPIES of any supporting documents such as contracts, invoices, receipts, etc. Be polite Be concise Try to give the company a "what's in it for them. Try to focus on the issue and maybe a solution. To Whom It May Concern: I am writing today to complain of the poor service I received from your company on June 12, 2020. Pay you some money to compensate you for something you have lost or had to pay for as a result of their poor service? Describe the item or service you bought and the problem. Include serial or model numbers, and the name and location of the seller. You may complete a complaint form online or download one of our complaint forms.