That's a bit harsh, especially considering the Mex route is operating at about 20-25% capacity most days. I'm booked in December and there are 3 seats blocked on the whole plane, all in First. Sure there may be more people with tickets who haven't reserved seats, but I'd have thought they'd be happy to reroute people on there, keep the money and not refund it, all while improving their load numbers on the Mex route. Guess is a case of "computer says no"