In World of Warcraft, a ticket usually refers to an active Help Request to a GM for in-game support about a bug, issue or problem in-game. Most tickets do not get resolved right away, unless it is a major bug newly discovered or an obvious and traceable harassment event.
Tickets are limited to a maximum of 500 characters. For complex issues requiring more than that, customers should email email@example.com for assistance.
An "Open Ticket" is for an issue that has not been addressed or resolved.
See Help Request for issues that GMs should consider valid requests.
You will know when you have an open ticket because a small ticket icon will appear just to the left of your Mini-Map at the top of the screen.
An "Escalated" ticket is one which has been passed onto a Specialist Game Master team, and this is normally done when a more complicated or thorough investigation is required. The waiting time for escalations can vary, but it usually takes a couple of days to receive a response.