Thread: denied boarding as non-rev, then what?

Well, in this topic I'd like to learn about what happens when you don't make it on a flight as a non-rev, as this is a topic which is not very well documented so far.

Personally, it has never happened to me, but it could happen one day, and then i'd like to know precisely what's next, as it makes the event more comfortable to deal with.

So, what happens when you don't get a seat on a flight you'd hoped to travel on?
-) Does the gate agent help you find an alternative (with their airline)?
-) How do you get your checked luggage back, in case you want to try your luck on another airline's flight?
-) How do you get out of the terminal, if you have already been stamped off by immigration (as international pax)?
-) What about the coupon they have taken from you; do they hand it back so you can use it again, or do they keep it and are you thus bound to fly with the same airlines' next flight?

I am asking because I started wondering about how to proceed if I check in for airline's X flight to XYZ with luggage, yet don't make it on the flight in the end. Do I need to hope for a seat on the next day's flight, or hope for a seat to another nearby destination, whereas there's also a flight with airline Y to XYZ about 3 hours later which I could try to get on?