At the bottom of every event's page is information about the event organizer. Contact info may be here.
If no contact info is there, then you can find more information at the organization page that is linked under the venue name on the event pages. The organization page will have an "Information" tab that should have contact info or a link to their website (if available) that may have contact information.
If you purchased tickets, you can find the link to the organization page in the "Need Help" section of your confirmation email.