Q: Credit debit without purchase

Does it show on your account's purchase history : See your purchase history in the iTunes Store on a Mac or PC - Apple Support ?

If not did you add/change payment or address details on your account : About payment card authorization holds in the iTunes Store - Apple Support ?

If it does show does the book show in the Purchased tab in the iBooks app on your phone (if t's compatible with phones) for downloading, or the Purchased section on your computer's iTunes/iBooks ?

Edit : as far as I can see there aren't paid-for books in the Nigerian iBookstore, so you must be using a different country's store - that is a violation of the store's terms (terms that you agreed to abide by), Apple permanently disable accounts for that

You cannot use the UK store unless you are here in the UK, contact Support and ask them to remove the balance so that you can put your real address on your account.