Bring Rachelle back!

I'm seriously ticked about them replacing Rachelle Lafevre as Victoria in Eclipse. I don't understand it. What's the reasoning? They say it was conflicting schedules, but Rachelle herself said that the schedules did not conflict w/ each other.
So were they not happy w/ her performance in Twilight and New Moon? So they decided it was best to replace her? That far into the franchise? When her part in the movie is biggest of all? I'm seriously irritated by this, and I'm sure many other fans are as well.