This was a new one on me (maybe I'm just naive)...when we arrived at our hotel in Buenos Aires, the taxi driver refused to pull into the hotel property and pulled up at the side of the road instead to let us out. When I paid him, he took the bill I handed from the back seat, his hands disappeared briefly behind the back of his seat, and then he raised his hand back up again, holding a bill of a lower denomination and telling me I still owed him more money.
Now I get why he refused to pull into the property...the hotel had signs in the lobby warning about rogue taxi drivers and i guess their staff would have assisted us if we had been right there.
I learned to say the amount out loud when passing the bill forward. Haven't had that problem since. I also insist on going exactly where I want to go, not getting dropped off "nearby" when the way is clearly accessible for the vehicle.
