Ahh I see what you mean now, call the police.

call the police. call your credit card company. If it was a simple mistake then no more will come of it. better safe than sorry.

He handed me the unit at the point where it asked for the vendor to input the price, while saying to me "put your pin in and press enter".

So as I put in my pin the machine registered it as the price, so a pin of 1234 became a price or £12.34

Your comment is interesting because it proves the subtlety of the situation.

Receipts show pin numbers? You sure?

Now let me say that at this stage I have no idea if this was a scam or just a genuine mistake.

I went to pay for a takeaway curry the other day at one of the few places that takes a card. They guy handed me the machine to enter my pin (1234 for the purpose of demonstration). I entered the pin and just before I handed it back noticed the price £12.34

Realising the price was not correct I told them it was wrong and they cancelled the transaction - with one receipt for me and one for him! Nice as he now has a paper record of my PIN!

I also am aware that they can do "cardless" transations (by phone or if the card is not working) by entering the card number. Alarm bells rang and as soon as I exited the shop I changed the pin number on my card at the ATM.

Anyone else come across this?