Why are K-pop light sticks and concert merchandise always sold out?

I need practical help with a K-pop Fan Questions issue.

The policy question: Why are K-pop light sticks and concert merchandise always sold out?
Useful context I found: Agencies balance lost sales against unsold inventory. Under-ordering angers fans; over-ordering leaves dead stock.

My specific situation: [Describe what happened, including dates and messages shown]
The outcome I want: [Refund, verification, appeal, account recovery, explanation, etc.]
Important constraints: [Country, deadline, booking/account status, documents already submitted, budget, or other limits]

Please:
1. Identify any missing facts you need before reaching a conclusion.
2. Separate platform policy, local law, and your own inference.
3. Give me the safest next steps in priority order.
4. Use current official sources where possible and flag anything that may have changed.
5. Draft a concise message I can paste to customer support.
6. Do not invent account access, guarantees, refund rights, or legal conclusions.