Start by using the formal complaint route rather than sending the same issue through several unrelated channels. A complaint should explain what happened, when it happened, who was involved if known, and what outcome you are asking for.
A short, organised complaint is stronger than a long, emotional one. Include dates, references, screenshots or documents where useful, and keep the request focused on the real issue.
If the matter is urgent but not a complaint, support should be used instead. A complaint route is for service dissatisfaction, dispute, or formal review, not for emergency action.