I lost a coin in a jammed pay phone: I got my money back, plus over $5 more.
I routinely get my money back, and other coins as well. You might be able to do the same thing. (Note: I used to fix this stuff for a living, so I learned how they work.)
Step 1: How they work
Coin-operated devices have a mechanical contraption that lets good coins drop through them. They stop and return bent or foreign coins and other objects. But sometimes, they just jam. There are two tricks you can use to get your money, and sometimes lots more money, out of them when they jam.