If you check the city pair now, is there a better flight available? Presumably you have some recourse, if there is a more favorable flight then ask ET to change it, if ET themselves won't work with you then I'd try the credit card company used to buy the ticket. If there is no better flight available then ask for a full refund and buy the cheaper flight.

If you simply bought a ticket way out in advance and the itinerary was exactly the same but price dropped nearer to departure then that's normal, but now that you're on a flight arriving many hours after expected and itinerary changed you have some teeth.