I no longer go to games, but if I did I'd be boiling mad if they rescheduled a postponed game that I had tickets for as a single 7-inning game. There ought to be a fan revolt over this.
I tagged the Nats on twitter and they have yet to respond regarding this. I fully plan on dragging my ticket rep into a broom closet this Friday and expressing my displeasure in how they handled it.