Getting our change back

Hi as a regular customer at milky lane Watercrest Mall in Hillcrest I have a big problem of not always getting my ten cents when we purchase ice-cream It's not a once of thing it's on going When you ask them why it's always the same issue of not having any change in they till point So tell me if 100 people leave they ten cents behind how much is that at the end of the day?Where does it go?