I stupidly type English when I was at the ATM and ended up with our own money.

So being completely sober I decided to change money at the exchange place in Hisaronu. I was sure they conned me three years ago.
They guy counted the money out in front of me starting with a fifty and VERY quickly counting the rest.
Not being trustful I stood in the door where he could see me and recounted. There was one fifty, 4 twenties and the rest in tens. Surprise surprise there was twenty short!!!!!!
So I returned and he took the money off me and counted it in front of me slowly.. Guess what there was 5 twenties this time.
I know I did not make a mistake but how do you prove it.