two more accidental overchargings (4 in a few days)

Being overcharged is so frequent that it's more a surprise when it doesn't happen.  Two more cases in the day after getting back to Guernsey.  In both cases I suspect it was a genuine accident.

At Doyle's garage, I got a new gas bottle.  Attendant guessed which size, and I paid for that.  But when we went to get the bottle, it was a larger size that I wanted.  I now had to pay the difference.  They wanted to do this as a refund for the first one, and then a new purchase for the actual one -- fine.  For the refund, I inserted same card again.  It asked for PIN, which was strange.  He confirmed it was a refund.  The amount was on there, but it didn't say whether it was a charge or a refund.  I entered PIN and asked for chitty.  It said "debited".  I queried it.  He said whoops, I had indeed been charged again instead of refunded, and he now refunded the total accrued, which was 2 * original amount.  I then paid for the actual bottle.  If we were applying a Hamurabi-style penalty-fits-error rule, I should additionally have been given the original amount again.

At Belvoir cafe on Herm, got coffee and ice cream etc.  Added up in my head.  He announced total.  It was more than the total I'd got.  Not by a lot, but it was more.  I said so, he added it up again, got my total, and that's what I paid.  Again, in "correcting" error, offset goes from -X to zero, not to +X.

Decades ago, a friend in Oxford admitted that they and their colleagues routinely short-changed customers and pocketed the difference.  I don't know whether this is behind some of the "mistakes" happening, but as long as there is no downside to trying it on, it will keep happening.  The recent example with the wine in the garage shows that it is possible for an employee to extract cash from an overcharge, even from a card transaction:

<https://wibblement.blogspot.com/2023/08/petty-scam-in-petrol-station-in-england.html>