See that big black button in the picture (left)? What would you expect to happen when you press it?
'Get my change' would be a reasonable answer to that question.
Look, even the little diagram shows where to put your pennies, then which button to 'press for ticket' and then where to look for your ticket to be dispensed.
And the final step in the diagram leads you to that big black button, with its illustration of change being dispensed.
Except, that in very tiny writing somewhere on this picture are the words 'no change given' (too small to spot at this scale).