MilesBuzz! - Passenger rights when downgraded - no compensation ???

This is the deal: An airline cancels a flight operated by a 3-class aircraft due to low demand one week out and rebooks the PAID F TICKET passenger to a same day flight in business class on a 2-class plane. Because of currency rate fluctuations the C fare is now as much as the F fare, and there is no fare difference anymore.

What are the passenger's rights regarding compensation if he opts to fly on that day?

Pretty much none. You are entitled to the fare difference, which is now $0.

Since it is paid F, why not just refund the ticket and travel on another carrier that does offer 3 class service?

Since the question isn't about miles and points, it's more appropriate for TravelBuzz (or, if the question specified the airline involved, the individual airline's forum).

Best,
Gary
aka gleff
MilesBuzz and Delta moderator