Make the first sentence usable
Lead with the reason for writing so the recipient does not have to decode a long emotional introduction. For a message about how to ask a bank to reverse an unfair fee, use this factual base: include the product or service, order number, dates, price, fault, prior contact, and supporting record.
Reduce the work of responding
Offer simple options, a narrow question, or a clear update that can be understood without another conversation. Request a specific lawful remedy and give a reasonable response date before formal escalation. Make the immediate next step clear enough that the recipient can answer without reconstructing the entire history.
Respect the boundary already visible
Do not exaggerate, threaten staff, publish private details, or demand compensation unrelated to the loss. Use payment, regulator, insurance, police, data protection, or legal channels for fraud, danger, or unresolved rights. A block, explicit refusal, legal restriction, or safety plan takes priority over the desire to explain more.