score:6
All taxis in Bangkok are required to use the meter, unless the passenger agrees otherwise.
Of course, as with in many other places in the world this does not stop the drivers from claiming that they are not able to use the meter for any number of reasons - however doing so is not legal.
In this case, if the driver refused to use the meter your best option would have been to get out and return to the staff at the taxi desk. Most likely the moment you started to do this the driver would have suddenly realized that his meter was working once again, but if not they would have been able to assign you another taxi. (Who's meter would probably also be broken, but eventually...)