I went to pay a cheque into my company bank account this morning. I knew the bank would be closed but was sure that I'd be able to do it using the ATM outside the bank.
So I put my card in, entered my PIN and selected "pay in" from the menu. The screen asked me how much I was paying in and I told it. It then spat out an envelope and told me to put the cheque and my paying in slip into the envelope and put the envelope in the slot provided.
That's when I realised that I didn't have a paying in slip. No problem, I thought, I'll just cancel the operation.
Except you can't. I'm standing there pressing the "cancel" button and nothing is happening - well except the queue of people behind me are starting to get a littel restless.
Finally, the only way I could get it to do anything way to put the empty envelope into the slot. The machine accepts it and prints me out a slip saying that the amount of my deposit is "subject to checking".
So now I potentially look like I'm trying to defraud the bank by paying in cheques that don't exist. I guess what I should have done is scribble a suitable message on the envelope before posting it. Perhaps something like "I know there's no cheque in the envelope, but I couldn't cancel the transaction - please ask your user interface designers to get a clue!!"