FWIW I am going through the same thing. I booked through Virgin two award tickets on Air France for November 18th. Air France "cancelled" the 11/18 flight and rebooked the tickets for 11/19. There is a flight at exactly the same time as my original flight on the 18th, but the flight number is now different. Virgin says they cant book me on it because there is no award space. I say "not NOW there isnt, but if you keep changing my booking then I dont really have a ticket at all". I say they are confusing the difference between when I want to voluntarily change versus they are cancelling my flight. I am sympathetic to the fact that it is a partner airline, but I agree that the terms do not make an exception. My new flight is 24 hours later. I am deciding whether to escalate and keep arguing.