When i used to run the BP servo i had to manage the ATM aswell (Fill it with cash and balance it everyday) And they are very clever machines only times we ever had issues with incorrect money being handed out we always found the money inside the machine as a rejected Note.    We did have a manager before me who inserted the $50 canister into the $20 slot and i can tell you no one complained about the money taken out that day except that manager LOL.

    Funniest thing was when customers would come up and say the machine has taken there card only to find out that the card never leaves there hand LMFAO