I had a requestor pm me that she recieved a liposuction dvd instead of my book.  I packaged it in the printouts in PBS specification.  The ends were taped (packging tape) and I made sure nothing would get snagged (I'm kinda anal about it).  The only way that you could open it is if you were the recvr and made the effort to open it.  She did say the wrapper was damaged.  Did usps ruin it and then give her something else?  I plan to give her her credit back, though I don't think either of us should be punished for the post offices fault, but I'm not sure how to go about this.  She already marked it wrong book. 

Is she sure it's the package you mailed?  Does she also belong to a dvd swap site?  I don't think PBS even allows dvds to be traded here, so it would be verrrrry strange to receive one instead of a book :-(

This happens sometimes. Here's another thread where we discussed a similar thing... http://www.paperbackswap.com/forum/topic.php?t=143369&l=25

It can happen.  If the package is ripped open, they do their best to get the right contents in the right package but it doesn't always happen.

I once had a friend order a stuffed toy.  She ended up with diabetic socks instead because of something like this!

Have the receiver go to the PO and talk to them about it.  She'll have to fill out some paperwork telling them what she was suppsed to get and they'll start searching for it.  Who knows, they may find her book.

We send and receive a lot of packages at work using UPS and I can tell you if a box breaks open they stuff whatever looks likely back in and tape it up.  We have received some of the weirdest stuff!  I'm sure the postal service does the same thing.

I once received a large box that was supposed to be a book. It was a t-shirt. I could tell from the postage label whatever they had orginally mailed was much heavier than a t-shirt. Never did figure that one out. I got my credit back and donated the basic black t-shirt which, unfortunately, was several sizes too big.

You shouldn't have to give the receiver her credit back. Since she didn't receive the book, it will be marked "lost" after the PBS estimated shipping time, and she'll receive her credit back from the site.