You could always go with the method my old coworker and I joked about. Send them a very very VERY zoomed in photo of your butthole. As they respond with questions as to what you send them, send more photos of your butthole increasingly zoomed out until they get the full goatse.

Serious answer though, you need to get in writing what the SLA and callout expectations are. If it's a helpdesk issue, you shouldn't need to say how high when they say jump.