What does your booking say when you look at it? If they've said they have moved you, why are you trying to rebook yourself?
It's pretty common to find all flights blocked out on a route if a cancellation is made in advance. This allows them to try and accommodate all pax without new bookings occuring.
There are 2 other threads in recent days which will no doubt be similar cancellations due to the Dreamliner issues. They discus this in a lot more detail.