Problem with ebooks purchased

I purchased an iPad on 28 January 2015. I loaded my 31 purchased ebooks, but unfortunately 4 books would not load. The message is either connection lost or token no longer available. Here is a list of the 4 books I am having trouble with: <br> <br> 1. Everything Body Language Book<br> 2. Hinds feet on high places<br> 3. Know your Bible<br> 4. An Introduction to healing<br> <br> Please help!!!!<br> <br> Kind regards<br> <br> <br> <br> Georgia Oliver