I've had this tried on me before, in Chicago where we're supposed to have super strict taxi laws. The correct response is to dial 911, not 311, and say you've got a taxi attempting to rob you. Notice next time you walk across an intersection at a stop sign, who comes to a complete stop more.. the average driver, or a taxi cab. Taxi's fear police way more than the average driver.
Is this not a bit of a waste of police time? Why can't you say "You tried screwing me, this is all I'm giving you. Got a problem? Ok, I'll call the police." Reading some of the comments in this thread it seems like people are seriously scared of taxi drivers. It's like any other business. If a restaurant tries to charge you for something you didn't order you don't pay them for it. You don't immediately call the police.
BTW: If it was me I would have walked out, when he attempts to accuse me I'd invite him to call the police. He's trying to change the price after the fact.
