[jaydub]

You should pay because it is a reasonable surcharge. Now in the case of an unreasonable surcharge... I have frequently had to deal with cabbies who make up bullshit fares, troll for other passengers, etc. The exact response differs but the general strategy is as follows.

1. Make sure all people / belongings are out of cab. This is obvious but can be overlooked when traveling with others.
2. Explain forcefully but calmly and reasonably that the situation is unacceptable. This can be hard to do at 4AM hammered but try.
3. Assuming that this does not work, hand the driver the amount you deem fit and leave. He will yell but simply ignore him. Be careful as you walk away, look into glass for reflections, be aware of surroundings, etc.