We got two more with this latest offer (the huge ones again), this time they came with white borders instead of the image fully wrapped though, not too thrilled about that as we didn't specify it.
Anyhow, was hoping they would collect via courier, but we have to return them through the post office (have they seen the size of the box?!) to get replacements.
they've also never asked me to return stuff when its been wrong, i have the white borders on some of mine too, they do it when the wrap would ruin the picture, says on the website and in my case it would have cut off the top of machu picchu and other stuff so i'm glad they didn't wrap, i was worried they would!
I agree Chris, that doesn't seem logical. Did you crop your photo so that it was the same overall ratio as the print size?
Photobox is far less automated than I expected it to be.
They do seem to have a lot of errors but certainly no problems getting replacements.