What could be worse than to be on the receiving end of a customer Twitter stream in a faltering organization? That is the fate of customer relations representatives who serve the New York City subways and its decrepit system. They are in a no-win situation. The subways are decades past upgrading their signals. Stations are dirty. Ticket machines are on-again-off-again. Delays are constant. Riders feel and are helpless to make things better. So they spew, and representatives try to answer calmly and with empathy. They can’t promise a fix because most likely there isn’t one. They can reply, “We hear you,” but that is empty. Nothing can be done once a complaint is logged. This is the worst position for customer relations to be in — powerless. The transit authority would probably be better off if it didn’t respond at all to riders’ venting, but it is making the effort anyway. Now, if it would only fix the system.