It seemed for a moment that we were gaining ground, only to have the man ultimately shut us down yet again.
On Tuesday my coworker alerted me to a wonderful fact about the candy and chip vending machine downstairs. When you put a dime in, the display registered the .10 increment while also letting your dime drop into the coin return. I walked down with 2 dimes and came back with 2 candy bars and 2 dimes.
On Wednesday I walked down with a few dimes hoping to cash in yet again. The dime went through, the .10 was registered on the display, but the dime actually went into the machine without dropping into the return. Fair enough. I pushed the coin return button and watched while the display cleared to 0.00 and my dime stayed inside the machine. The same thing happened on Thursday to my coworker. He put in 7 dimes, realized the chips he wanted were .50, selected the chips, and promptly received the chips and no change.
The machine, it seems, is making up those lost dimes.