I am trying to post one book. When I put the ISBN # in PBS, another book and cover comes up. How can I get this changed so that the proper book appears?

A confused SueG

Sometimes this is an error. And sometimes it is the publisher reusing a number. Either way, this is not easy to fix.

You need to document that this number was never used on the other book. Then submit a data edit.

At one point in the 1970s, one publisher bought out another and reused hundreds of numbers. So a bunch of romances and science fiction all share ISBNs.  Box sets will often have one number for the whole set, which can get applied to the first book posted.

It is often easier to post without a number.  A short ISBN will be assigned.

The cover image does not need to match.

I've had this or something similar happen before but they weren't literally different books. Strangely were published under two different titles at different times. 

The title of the same book may well be changed, because of issues such as Canadian/UK versions, movie releases, or reprints.  I once found the same book, title, and a different pen name after one of the author's pen names became more famous than the other.

Then there are the cases of two books having one ISBN. 

Responses to an earlier post in this thread...

"The cover image does not need to match."

The title and author shown in the cover image do need to match the listing even though the image does not need to match a specific edition. Also, if a publisher's name shows on the cover image it is best (but not required) if it matches the listing whenever possible. (Caveat: Sometimes the publisher displayed for a given listing is incorrect, so this can be a gray area). In addition, if a cover image indicates that a book is for a Large Print or Audio book, then the cover should be in agreement with the listing.

"You need to document that this number was never used on the other book."

If the ISBN has been reused by a publisher then one can never document that it has never been used by the other book. I think the rule is that if a book having the same ISBN  but a different title and author is currently posted on the system or appears on any member's wish list then the title and author cannot be changed for that ISBN. In such cases, books having the same ISBN can only be posted without using the number and PBS will assign a short ISBN to it.