I recieved a book last week that I had to mark as a problem swap (only my second RWAP in my time here *knock on wood*). I sent the sender this polite PM:

The copy of 'Pride and Prejudice' you sent to me is not in swappable condition. The binding is showing and, upon opening to the first chapter, I could see that the bottom corners of the pages bound into the book were hanging free.

With the first few pages of the book clinging very delicately to the binding, it makes the book very difficult to read for class. I would like to request that you return my credit so that I could select another copy of 'Pride and Prejudice' to read for my class.

I've not yet heard back from them. How long do you usually give someone to respond before marking that the sender is not going to resolve the problem swap?

Usually a week...but do give a deadline, after which you can mark it as unresolved-and probably go out and buy another copy!!!

more information from the help docs:

Before submitting follow-up on a problem swap:

• You must have sent a PM to the sender, clearly asking for a response (and a credit refund if that is desired)
  • You can send the PM during the process of marking the book received, OR using the PM button on the swap in your transaction archive as described in How do I contact another member?.
• You should allow the sender a week at least to respond to your PM and resolve the swap.
• You should check the member's bookshelf (by clicking his or her highlighted name on the swap, which will take you to his or her bookshelf or profile, where you can click the Books button) to see if his or her account is on vacation.  If the account continues to be on vacation for more than a week, you can contact us to find out when you might expect a response from the requestor.

Also Erin, check your Credit Transaction Registry.  Some members refund the credit without answering the pm.

You should have an option under the problem transaction that says something like "Sender never responded". If you choose that, pbs will contact the sender and let them know that they need to respond. You may want to do that before you mark it unresolved. I've had to use that a few times and every time, almost immediately the other member responded.

When you mark the sender did not respond button, PBS sents a very harsh sounding email about it.  PBS does not get in the middle of problem swaps.  But they come down very hard if you fail to respond to problem PMs.

Of course, I've also had folks who refunded my credit without any PM.

You may never get your credit back. I have had 3 that I never gotten back.