So this was about 12 years ago when I was still fairly fresh faced and happy to help every customer with a smile... this may not be as bad as some of the other ones I've seen on here, but 12 years later and I still remember it like it was yesterday. I used to work for a brand that sells everything from Clothes to food to home ware.
One day I was serving a customer who was buying a variety of home wares- pots/ cushions etc. probably amounting to around £200 total, not the biggest sale but by no means minuscule. Transaction is going well, I offered our company CC just in case she was a mystery shopper and hit all the points on my mental checklist of serving on the tills.
We get to the payment part and her card declines, once, twice, three times... it cited auth code on the till - this was before the days of Chip & PIN so she needed to call her bank.... apparently that wasn't satisfactory
CW: Crazy Woman
Me: I'm afraid it's saying you need to call your bank, unfortunately the card has declined.
CW: try it again.
Me: I've tried it three times, unfortunately it's giving me the same message, how about this, I can either hold the items for 24hrs here with your name on and you can get everything sorted with the bank, or alternatively if you have another form of payment I can get that through for you now.
CW: Well it must be your machines.
Me: The machines have been working fine all day, the error message is specifying the card.
CW: Get me your manager.
Manager is within earshot and had been keeping an eye on it so wanders over.
M: Is everything OK here? How can I help?
CW: Your card machines aren't working and SHE is saying it's my fault.
M: Well let's see what we can do *opens up next till and runs everything through* unfortunately the card is not going through I'm afraid, do you have another form of payment with you? Otherwise we'll happily hold your items for 24hrs if you want to call your bank?
CW: WHAT DO YOU MEAN IT'S NOT GOING THROUGH? HOW DO YOU SLEEP AT NIGHT? YOU'RE RUINING LIVES WITH THOSE CRAPPY MACHINES.
M: Well madam, I sleep very well at night, I'm not sure how that is relevant though in this case.
CW: *stomping off without the items* You'll be hearing from my Lawyer!!
M: Okay, thank for visiting, enjoy the rest of your day.
I had never seen my manager react to a customer ever... she was actually shaking! We never did hear from her lawyers, Head Office never told us if she complained (we'd have had a meeting about a customer complaint - those were taken seriously) but we did find out from another employee who had seen the whole thing happen that she came in a day later when me and my manager were off to buy the items - apparently her bank had sent out a new card ahead of that one expiring and deactivated the card without telling her.... Ah the joys of being screamed at for something you didn't have any control at.