Write "To:" on the left hand side of the page, two or three inches from the top, followed by the name of the recipient. On the next line include the person's title (for example "Manager"), and on the next two lines write her address.
Skip a line and write "From:" underneath the recipient's information. Include your name, title (if applicable) and address on separate lines.
Begin with a salutation such as "Dear Ms. Brown," several lines after your contact information. Skip another line to begin the actual letter.
State the purpose of your letter in one or two brief, direct sentences, such as "I am writing to get a replacement for a faulty mp3 player I bought from your company." This statement clearly explains the situation, reveals the writer's intention and calls for action from the recipient.
Start a new paragraph that explains the details of the situation. For example, "The mp3 turns on, but the image on the screen is jumbled" describes the exact problem. Mention that you have tried to fix it and the problem is no fault of your own, but a flaw with the product itself: "I have tried turning it on and off several times, but I still get the same screen. The battery is fully charged, and it has never gotten wet or been dropped."
Conclude by repeating your call for action from the recipient. Leave them with a clear idea of what you want them to do: "I look forward to receiving either a replacement product or a reimbursement of my money."
End with a short, polite phrase such as, "Thank you for your time." Add your name and sign the letter.