It's great that you handed it in.
A few months ago, I took out £300 from the bank. Or I thought I did. I withdrew it and left it in the slot. 
The bank is just across the road from me, and I got home, went to put it in my purse and couldn't find it.
I ran back to the cash point and of course it wasn't there. I was walking around, babbling to myself, I was just gutted.
And then, this lovely Italian guy said to me: "Are you looking for something?"
And I was "yes, I took some money out and I think I left it, and I don't know what to do and it's gooooone - waaaaah!"
And he said: "how much?"
And I said: "£300".
And he said: "is this it?" 
And I screeched all over him and he gave me a great big hug and it was the best feeling!
So if someone does get it back, be assured that it will make them very, very happy! And you might get it anyway, if no-one claims it. 
