Writing: B1/B2 - Lesson 10: Writing a Formal Letter of Complaint

Writing: Functional Writing B1/B2

How to Write a Formal Letter of Complaint

Listen to the key phrases and examples.

What you will learn: By the end of this lesson, you will be able to write a clear, polite, and effective letter of complaint using the correct formal structure and language to get a result.

Before You Start 🧠

Key Vocabulary (Click 🔊)

Let's learn these important words for writing a formal letter.

Complaint

| ការតវ៉ា

A statement that something is wrong or not good enough.

Formal

| ផ្លូវការ

Serious, polite, and correct. Used for business or official letters.

Refund

| ការសងប្រាក់វិញ

An amount of money that is given back to you.

Inconvenience

| ការរអាក់រអួល

A problem or difficulty that is annoying but not serious.

The 4 Key Parts of a Complaint Letter

A good formal complaint is clear and follows a simple structure. Do not use contractions (e.g., use I am, not I'm).

1. The Opening

Start politely and state your reason for writing.

• Dear Sir or Madam,
• I am writing to...
• I am writing to complain about...

2. The Problem

Explain what happened with clear facts (dates, times, order numbers).

• On [Date], I purchased...
• Unfortunately, the product was...
• I was very disappointed to find that...

3. The Solution (Your Request)

State exactly what you want the company to do.

• I would like a full refund.
• I must insist on a replacement.
• I would be grateful if you could...

4. The Closing

End the letter politely and formally.

• I look forward to hearing from you.
• Yours faithfully,
• [Your Full Name]

Example Formal Letter

Click 🔊 to hear each paragraph.

Dear Sir or Madam,

I am writing to complain about a coffee machine I purchased from your website (Order #8820) on 25 October 2025.

Unfortunately, when I used the machine for the first time, I found that it does not heat the water. The coffee it produces is completely cold. This is very disappointing, as the product was advertised as "high-quality".

To resolve this problem, I would like you to send me a replacement machine. If this is not possible, I must insist on a full refund of $50.

I look forward to hearing from you and a resolution to this problem within 10 working days.

Yours faithfully,

Vanna Chen

Practice What You Learned 🎯

Quiz: Choose the Most Formal Phrase

In a formal letter, which phrase is the best choice? Click "Check Answers" when you're done.

1. How to start your letter?

• A) I'm mad about my order.
• B) I am writing to express my dissatisfaction with...
• C) I want to tell you about a problem.

2. How to ask for a solution?

• A) I would be grateful if you could provide a full refund.
• B) Give me my money back now.
• C) I just want a refund.

3. How to close the letter?

• A) Write me back soon,
• B) Cheers,
• C) I look forward to your prompt reply.

Your Writing Mission ⭐

Write Your Own Complaint Email

Imagine you bought a new pair of headphones online. When they arrived, only one side produced sound.

Write a short, formal email (3-4 sentences) to the company (support@techstore.com).

1. Use Dear Sir or Madam,
2. State the problem (Order #123, headphones broken).
3. Request a solution (a replacement or a refund).
4. Close with I look forward to... and Yours faithfully,

Try writing your final draft in the comments section!