A useful complaint explains what happened and what response you want. In a fictional delivery example: "My order arrived today, but one of the two notebooks listed in the confirmation was missing. Could you check the order and arrange the missing item or explain the available options?"
Add the relevant order reference through the appropriate private channel. Give the date and product identity accurately. Avoid sending personal details to an unverified public account simply because it uses the company's name.
Describe observations, not motives
"The package contained one notebook" reports something you can observe. "Your staff deliberately ignored my order" assigns a motive without evidence. Factual language makes the practical issue easier to investigate.
If the organization asks for a photo or additional information, respond through its official process. State any preference clearly: "I would prefer the missing notebook rather than a substitute." That preference does not by itself establish which remedy is legally or contractually available.
Practice reducing an angry first draft to the essential facts and request. Keep necessary evidence while removing repeated accusations. Ask a partner to identify the problem, reference, and requested action. If any is missing, add it. The aim is a message that allows a useful response, while preserving a clear record of what you reported and avoiding promises about outcomes you cannot control.