Help please re-enabling access to my e-book

Hi, I bought an e-book from Adobe last year which I am no longer able to access. The email address I thought was used for my id had was not recognised.  On the advice of the Adobe help chat line, I have just set up a new Adobe account; this appears to have been set up successfully.  However, when I try to open my e-book, I get the following error message

"The vendor account you entered is not associated with the item you are trying to open. Try again."

Please can you suggest what I need to do to re-enable access to my e-book?