I got locked into our NOC once, years ago. Despite my very explicit instructions that all electric door strikes must fail to the unlocked state, the contractor did whatever they please.
I called facilities, but they couldn't get the door to release either. Fortunately, we had a big plate glass window into the lobby (so that people could see the pretty NOC without having to enter the NOC).
I'm a pretty big guy, so I simply threw a swivel chair through the larger of the windows (the most expensive one) as a sign of my displeasure. Once I got access to my tools, I ripped the entire door frame out of the wall.
I had no more trouble getting into and out of the NOC that weekend. :-)