Can't contact fulfillment center

[#1]

I have downloaded a book to my iPhone but I can't get the book on my iPad.  Account is authorized and I have have enough device space.  The message I receive says the server can't contact the fulfillment center check the internet connection but that works fine too.

How do I fix this so my book can download to my iPad?

[#2]

I have downloaded a book to my iPhone but I can't get the book on my iPad.  Account is authorized and I have have enough device space.  The message I receive says the server can't contact the fulfillment center check the internet connection but that works fine too.

How do I fix this so my book can download to my iPad?