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.
Step 2: Push the Coin Return knob -- HARD and FAST!
Flick the coin return knob hard, fast, and over and over. There's a magnet inside that grabs Canadian coins and slugs. A wiper tries to wipe the coin off of the magnet, but it rarely gets all the way to the far edge of the magnet, so a little bit of the coin holds on. When you release the coin return, the coin just slides back on to the magnet, and you're right back where you started.
Instead, flick the return knob hard and fast, over and over as fast as you can, and try to fling the coin beyond the edge of the magnet. The coin will drop in to the coin return like it's supposed to do. Repeat as needed. If that doesn't work . . .