This is actually a nice story. It is about an interaction my sister had when she worked in business customer service.
Sister: Sis, New secretary: NS
NS: Hi. I work for [company] and I was looking at the company telephone bill. It doesn’t look right to me. My boss says I’m being stupid because [telephone company] wouldn’t make a mistake.
Sis: Let me have a look at it. At first glance it looks like something is amiss, and I think it is fairly involved, so I would like to let you go and go over it more thoroughly. Could you give me a call-back number.
Sister went over the bill, then went back some distance in time until the errors stopped happening, made the appropriate adjustments, and called the New Secretary back.
Sis: Hi. This is [agent] from [telephone company]. And your instinct was correct, there were errors which I have corrected and adjusted the [company’s] account. Tell your boss you were right, there were errors, the refund is [large amount], and he owes you lunch.
( The correction was somewhere in the neighbourhood of $15,000CAN )