What happens to unclaimed money?

I used the cashless system at CTICC Jazzfest. Annoying with long lines to start with, didn't have exact amount on my card and so had to endure enitre experience again. Now there is a small balance on my card, and I am struggling to reclainlm it. Not to mention that I am being told that there is (another) fee to cash out. Next rume I will avoid the concessions. It has left a bad feeling about Jazzfest, and definitely Howler. What happens to unclaimed money?