"You must make loads of money, and I bet you don't pay tax" - none of their business, and of course I pay tax!
"Well that was a nice and easy earner for you" - dealing with obnoxious idiots is never easy.
"Hi, I saw you for an hour booking last week but I left after 40 minutes. Could I redeem my remaining 20 minutes this afternoon?" Seriously? No!! "Well how about tonight then?"