Ravi from Kanpur’s complaint letter began “I am extremely disgusted by your pathetic service.” His frustration was real; his tone cost him.

A good complaint letter is firm but polite: say what went wrong, give the key details, explain the effect on you, and state clearly what you want done. Calm, specific language is usually more persuasive than anger.

Striking the Right Balance in Tone

A complaint can be formal or semi-formal, depending on who you are asked to write to. A company manager or local council you do not know calls for a formal letter, and a landlord you know by name suits a semi-formal one.

Either way, keep your anger off the page. Emotional outbursts weaken your argument, while specific facts are difficult to dismiss.

For how to choose between the styles, see choosing the right tone.

Useful Language for Complaint Letters

This table gives phrases you can adapt for each stage of a complaint.

Purpose Useful language
Stating the problem I am writing to complain about…
Giving details The order was delivered on Thursday with the number…
Explaining the effect As a result, I cannot use it for my event.
Requesting action I would be grateful if you could send a replacement.
Setting a deadline politely I would appreciate a reply within five days.

Practice Task and Model Letter

Here is an original complaint task in the format of the IELTS sample tasks.

Practice task (written for this post)

You should spend about 20 minutes on this task.

You recently bought a kitchen appliance from a fictional online store. It arrived damaged and does not work.

Write a letter to the customer service manager. In your letter:

  • give details of your order and the appliance
  • describe the fault and how it affects you
  • say what you want the store to do

Write at least 150 words.

You do NOT need to write any addresses.

Begin your letter as follows:

Dear Sir or Madam,

Anger gives the reader nothing to act on, so compare these two lines.

Incorrect: “Your pathetic service has ruined my life.”

Correct: The cracked machine has caused me considerable inconvenience, as I need it for a family gathering next weekend.

It states the practical inconvenience calmly rather than venting anger.

Here is a complete model letter for the task.

Model letter (illustrative Band 7)

Dear Sir or Madam,

I am writing to complain about an espresso machine that I bought from your online store. It arrived damaged and does not work.

I placed the order last week (order number 48210) and paid ₹7,499 by card. It is a compact two-cup model, which I chose for my small kitchen. The machine was delivered on Thursday, and your website described it as new.

When I unpacked it, I found that the water tank was cracked. I then plugged the machine in, but it would not switch on, and a red light kept flashing. As a result, I cannot make the coffee I had planned to serve at a family gathering next weekend.

I would be grateful if you could send a replacement machine within five days. If that is not possible, please refund the full amount to my card. I can send photographs of the damage if you need them. Please also tell me how to return the faulty machine.

I look forward to your reply.

Yours faithfully, Rajesh Sharma

Why It Works

  • Task Achievement: the first sentence states the purpose, and each bullet point has its own paragraph with specific details.
  • Task Achievement (tone): the tone stays formal and calm throughout, with no contractions.
  • Coherence and Cohesion: “When”, “then” and “As a result” link the fault to its effect.
  • Lexical Resource: “place an order”, “send a replacement” and “refund the full amount” are natural collocations.
  • Grammatical Range and Accuracy: it mixes simple sentences with conditional and time clauses.

Extending Each Bullet Point

Give the request as much room as the fault, because the last bullet point is easy to rush. For paragraph-by-paragraph advice, see covering each bullet point.

To soften requests further, see polite ways to make requests. For complaints outside the test, see complaint letters and emails.

Tip

Ask for one outcome first and name a fallback second, as the model does with the replacement and the refund.

Key Takeaways

  • Stay calm and objective, even when you are annoyed.
  • Add specific details, such as an order number or a price.
  • Ask for a clear solution and give a polite deadline.
  • Give each bullet point its own developed paragraph.

The bottom line: Anger shows in adjectives, but firmness shows in a clear request and a polite deadline.