Re: One of those sounds like a computer error
Here in the USofA, I once used an automated check-out machine at the home improvement store, gave it a $20 for a $17 purchase and received three $10 notes in change.
Being an honest kind of guy, I went over to the "watcher" and presented her with my receipt, the three $10 notes, a smile, and told her, "No."
I have never seen the staff at Lowe's move so quickly before, or after. Must have been a one time event.
They opened up the machine, handed me my $3, and I left, while they attempted to figure out how many people before me had neglected to inform them of the error.
Best Saturday morning fun I've had outside the bedroom in...forever.