It is folly to fool around with law suits and DOT complaints (even if there is a DOT complaint to be had). That may be a good idea at some point down the road, but for the moment, OP needs a solution to his problem.

We don't know that OP is a USN, where he purchased the ticket, where he originated or any other details and he has not posted those here or in this cross-posted thread which has now properly been Closed because of the poor advice to start one over there.

The easiest and fastest thing to do, presuming that OP qualifies, is to obtain a visa. If the rescheduled flight is otherwise acceptable, all is well and the rest of the foolishness drops off.

But, until OP provides some solid information, it is really hard to provide helpful advice on which he can act.