You were right granfromafar, I would also have handed it in. Once I took £50 out from the Waitrose cash machine as I going out for the day with a friend the following day, I think I picked it up from the cash machine but maybe I didn't, or when I went to pay (by card) at the self check out maybe it dropped from my purse, anyway when I got home it was gone! Went back to the store but no one had handed it in, or staff were telling untruths, either way, I never got it back, so someone got themselves a bonus that day, and it wasn't me!
Another time, distracted by chatting to my friend as we paid for shopping, I inadvertently left my credit card in the machine at the till. I discovered this around 4 hours later and I immediately rang to cancel the card. The lady at the credit card company told me that my transaction was showing up, PLUS a transaction to Argos for £25, made about an hour before I rang her. Someone, maybe customer behind me, or check out girl, watched me put my pin in, and calmly collected my card and used it with it's pin in Argos about 3 hours later!
So obviously everyone is not honest, good on you granfromafar and all others who are honest. Wish one of you had found my money or my card.