I was at the supermarket today, and the woman in front (early 30s at a guess, pregnant with two children) held up the entire queue for over 10 minutes as one card was rejected, then another, and then she took a phone call (?! but I guess maybe to the bank to confirm it was her) then had to download an app and eventually paid. I felt sorry for her, and if her shopping had been under £20 I'd have offered to pay for her, but she was doing a big shop.
Twenty minutes later, we're both in the shop next door, and - yay - I'm behind the same woman in the queue again. EXACTLY the same thing happened (minus the phone call) - one card was rejected, then another, then she needed to do something on her phone to get it to work. At least in this store, eventually the cashier asked her to step to one side while he dealt with the backlog of 5-6 customers who'd built up behind her in that time.
What on earth was she thinking? I totally understand how some people have cards that are maxed out, but surely she should understand that if it was maxed out in one shop, it would be in the next. (Unless it's some sort of fraud that I don't understand.) I was hot, sweaty and bothered - mostly because my parking was about to expire - but also felt really sorry for her kids, as everyone was staring at her.