A long long time ago, when I worked at an amusement park, there was a line for the bathrooms closest to the kiddie section of the park and I was stationed at a customer service kiosk in the same building. One woman had the audacity to, right in the middle of the line, get pissed at me for allowing a bunch of adults to use the restrooms because that meant her children had to wait. It was so dumb that I just smiled and nodded, and she kept going. By the time she left, everybody in the building hated her, and I even had another woman walk over and shake my hand.

Same job, I used to gauge whether or not I would actually take complaints based on whether or not I agreed with them. Employee shitty with safety procedures? Sure, here's the paper, read what I have written and sign if you agree. You think the music is offensive in one section? Right. Ok. I'll... tell my managers... just... don't worry about it...

I also had a customer call when I was nearest to the phone at a store I worked at and complain that the manager was a dick to them. I happened to like that manager, so I pretended to be his boss, listened intently, and told nobody.