How to reach a human, what to include so the first reply is the useful one, and what response times to expect.
A ticket with these five things usually gets a real answer on the first reply instead of a request for more information.
Response targets depend on your plan; paid plans are prioritised and Enterprise agreements can carry committed times. The current commitments are on the SLA page.
If something looks broken platform-wide rather than account-specific, check system status first — it is faster than a ticket.
Do not wait for a reply before protecting the account. In this order:
Send the raw signal, the timestamp and the account name — that is usually enough to answer on the first reply.