Complaint is a gesture or statement of disagreement or discontent. Its a kind affliction that indicates a hurt has been caused to the complainant, to business, a delay in an order, a mistake, a delay in a bill, rent payment, any financial issue or any dissatisfaction in the course of business can give rise to a complaint letter. A letter of complaint also points out an infringement, violence or disturbance of certain predefined lines for the course of business. It is a formal letter so it should be concise, authoritative, factual and constructive.
Usually a complaint letter is based on some salient features which each letter should have a situation. Now situation can be different according to the requirement of the scenario. The situation you are going through should be mentioned clearly. The complaint letter should be having details of what has happened and what made you write this letter. Do mention a problem with causes and effects. The letter should be having a solution to the problem, without this the recipient will not be able to understand what you actually want or your requirements. If you have already taken an action and still the problem persists, you can also give a reference of that.
As the complaint letter is an official document so, it should be written well in a formal way, should also be presented professionally. Complaint letter should be written on the letterhead of the company as it is an official letter, having name, address and contact number of both sender and the recipient. Tone of the letter should be polite but decisive. The letter should actually y address to the co-operation of the two parties to an agreement and their relationship. So, it should be based on a real issue and constructive problem solving strategy. End your letter in an encouraging way, to make the recipient respond positively. Avoid aggression or rude statements, sign and stamp the letter. Here is a chance for you to have a sample of a complaint letter for your convenience.