If you have checked the "no winner" box then the stakes are not returned, the market gets settled "This event is over" but stakes remain. In order to abandon an event and return stakes you must click on the "Abandon this event" link on the upper right side of the market, next to the Edit link. Only then the stakes are returned.
IMO it is you the one who have to contact an admin and ask for assistance.
__________________ When I'm good, I'm very good...but when I'm bad, I'm better