Unfortunately, there isn't anything you can do at this point. It's likely the member just missed it, as you initially did. You can message them and ask for your credit back, but they are under no obligation to do so, and I, personally, wouldn't bother.

I would just grin and bear it. It may be a book that they didn't read, and it was just as easily missed by them as you. 

It's very possible that the poster didn't read the copy she sent to you, so this one underlined section was missed.

If that is the only thing that renders the book unpostable, you can post it under the "textbook exception" or offer it in the Book Bazaar. I agree with caviglia in that I wouldn't bother asking for a credit back at this point.

I'll just echo what Sophia said:

you can post it under the "textbook exception" or offer it in the Book Bazaar.

The textbook exception allows you to post it to your bookshelf  and PM to get permission before mailing.  And the Book Bazaar would be a great idea in this case.  There's a thread for unpostable wish list books.  You can ask a credit for your book there, and often the books are requested quickly.

There's no rule saying you can't ask her for your credit back now, but most members don't do that if they missed the damage when they were marking the book received.

It's quite possible that they missed it.  If you already acknowledged that you received the book then you are OOL.

What they said (above).

Awhile back we requested a PBS book DD needed for class.  When she was finished, I posted it again for another member. The book was requested this morning and I mailed it out this afternoon.   I checked the book when we received it, again when I posted it, another time before accepting the request, and several times before/during wrapping.  I haven't read the book myself, didn't look at every single page, and although it's been checked several times...there is still a small chance a few words or sentences are underlined somewhere, despite my efforts.

We do the best we can.  But all PBS members are (or should be) human, and once in a while we miss something.  Unfortunate, but it happens.

You cannot RWAP after it has been marked received normally, that process is permanent.

Odds are they missed it, or forgot it was there. You can PM and ask for you credit back if you like, but the sender has no obligation to give it back to you either. It may be easiest to just use the textbook exception and PM the requester for approval before sending it, or offer it in the Book Bazaar.

Once I mark a book received in good condition, any problems I discover I consider MY problem and would never PM after the fact to ask for a credit back. If the problem was minor enough that I didn't notice it when checking the book over upon receipt, I certainly can't fault the sender for missing it also. Lots of folks don't read the books they are posting and so would not likely look through every single page.

A few years ago, I missed a couple of problems on check-in, not noticing the issue until weeks/months later when I went to read the book...which I basically used as a lesson to myself to be more diligent in looking books over as they come in before marking them received. Still, one instance of underlining is not something I'd beat myself up for...I would read it, donate it to the FOL sale or the community bookshelf at work and move on.

Cheryl

I got a book, checked it, marked it as okay, and then later discovered that it had highlighting, but the highlighting was so light I had missed it flipping through the first time.  It was arguably a textbook, and I figured if I had missed it when I was checking for it, the sender probably did too.

Now if I got something highlighted all over the place in that awful fluorescent yellow... :-(