Ais written to deal with situation or a problem when any other means of communication have failed to communicate the problem. It formalizes the problem situation by putting it into writing .most complaint letters are written for personal situation, but there are others written for business situations.
This normally contains the address. You type the name of the person you are addressing the letter that is the contact person. Then type the title the persons holds , the company name .you could use the department or complaint office address if the contact name is not available .include the zip or postal code ,street if applicable and the state :
Name of the person the letter is addressed to (contact person),
Title of the person,
The company name
The complaint office (if the name is not available),
Zip or postal code
In salutation it is better to address the letter to a specific person that is you should use “dear first name” this makes the letter look formal .but in situation that your letter is generic use “dear sir or madam” do not use initials.
You could give your letter a headline but it is optional, but for aformal letterit is good to give it a headline. this includes the reason for writing that is ;RE : ( reason for writing ) e.g. RE: complain of a product order on (date ) and delivered on ( date ) and it had (state your view)
The letter should contain reasons why you found the product or the service not satisfying and why you are disappointed with it. You could state the problem you think it had and give solutions of how they would handle the problem if it is experienced again. These details should fit in two to three paragraphs as the letter should fit in one A4 page.
Use the complementary “yours sincerely” if the letter is specific, the name of the addressee is known or use “yours faithfully” if the letter is generic. Skip 3- 4 lines and type your name in full. If there is any enclosure use Cc. (to whom you are sending the letter to. print the letter and sign in between the complementary closure and your name.