I ordered a book and the sender said it had been sent 12/12/2007,  After the 26 days and no receipt, it was taken off my list and I rec'd credit back for it.

Today 1/14/08 it arrived--postmarked 1/9/08!!!

I:

A. Don't know how to give the credit for it.

b. Don't know if I should--or want to--since it was mailed a month after the request!

Technically, you are supposed to go into your transaction archive and mark the book received.  That will take care of giving the credit automatically.

More from the help center:

Books that arrive with a late postmark need to be marked received normally, and the information about the postmark should be recorded in the survey portion of the Book Received page.

• Providing the late postmark in the survey portion of the Book Received page will generate an auto-email to the sender of the book, reminding him or her that late Mailing is not acceptable at PBS.
  • The email includes the information that the late postmark could have been entered in error
  • The email includes the information that sometimes postmarks are delayed a few days, even if the book was mailed on time
  • The email includes the information that if the late mailing was agreed to by the requestor, this is not a problem
• You can contact the sender using the text box on the Book Received page:
  • Please be gentle!  You can't know what might have delayed this shipment
• If the book was declared lost in the mail and you requested a second copy because you thought the first one was really lost:
  • You can ask for your credit back in your Personal Message
  • You can note this information in the Comments box at the bottom of the Book Received page: this will go onto the sender's record.
• A pattern of late mailing will cause account suspension and possibly termination of membership
  • Sometimes late mailing happens for very good reasons, but chronic late mailing will not be tolerated

Also:

When a lost book arrives, you must mark it received.

To do so:

• Go to your Transaction Archive:

  • From My Account: click the link "Transaction Archive" in the yellow bar at the top of the page
  • From anywhere on the site: place your cursor over My Account in the toolbar at the top of any page on the site and choose Transaction Archive from the menu that drops down
• Sort the Transaction Archive by "Requested by me" - "Lost in mail" - "Title" - "Descending"
• Locate the Lost transaction for this book in the list.
  • If there is more than one Lost transaction for this title, check the sender's name on the right of the transaction against the name of the sender in the return address on the package you received.
  • Click on the transaction.
  • The next pages are the regular Book Received pages:
    Click on the next page
    Provide more information about the swap on the next page
    • you will also have the option to send a message to the sender of the book
    • you will also have the option to provide comments on the swap that only we will see
• Both your account and the sender's will be updated when you have done this.

Edited: Others answered faster and better! LOL!

Also if it had stamps on it, the person really could have mailed it in Dec but it was waylaid various places and finally postmarked in January.  It may not have been the sender's fault.

If it had the printable postage though, the above does not apply and the person mailed it late.