The basic principles of writing all complaint letters:
1.Be polite.
2.Explain carefully and tactfully what is wrong
3. include any details necessary to identify your claim –dates, catalogue numbers, styles, order numbers, and the like.
4. indicate the loss or inconvenience you have suffered (if any), but do not aggressive.
5. Explain, in general, what you believe the company should do about your claim; but do not be unreasonable in your request.
6.Avoid negative accusations or threats, such as, ‘l demand’, ‘l must insist’, ‘you will have to’, ‘why can’t you’, etc.