Q: Link to Customer Support for Photos Print Books

I ordered an 8”x6" softcover book with 68 pages, and it arrived today! It looks very good. However, there are two blank pages (one photo that spans two pages, and also happens to be the cover photo in a different form) and one other photo, missing from the printed book. I went back to Photos to check and see if I missed something, but my book layout that was submitted has all the photos on every page.

Does anyone know of any refund page or way to contact customer service for Apple printed material? It is not very obvious how to contact them.

Thanks!