A cashless society will work just fine, I'm sure.
I used my debit card at the gas pump the other day. I accidentally hit the diesel button because I'm old and stupid now days. I put the handle down and went inside to tell the clerk to cancel the transaction and give me $20 on my card as credit which went right through as completed on my online statement. She did, but now there is a $150 charge pending on my card that is not going away. This has happened before on a canceled charge, and the card company says it will automatically go away in 7 days. Nothing I can do about it, and my $150 is tied up until then.