I only emailed them a couple of hours ago but Schiffer have already got back to me and offered to send a replacement book. I can muddle through with what I have until I get it.
I've also had the Book Depository asking me to send them pictures of the book and the lack of pages - not sure how to do that yet. I'm not returning the deck but if other sets have been affected, it's only a matter of time before other customers complain.
If you have a scanner, that's the easiest way to get pics of a book in my experience. Or there are apps that scan to pdf or jpg from your phone. (I'm new to smartphones, still drunk on apps! ) Images showing that the page numbering goes from (for example) 11 to 16 directly, omitting 12 to 15, would be what they need I should think?