When I set up my ebook site, The Cafetorium, I purchased the eStore script and a bundle of ebooks and software packages.
I set up the eStore, loaded in the product database, which consisted of all the ebooks and software in the bundle. Then I set it to work.
Yesterday I received an email from the owner of an eBook saying that they had never issued that eBook with resale rights of any kind.
Of course I removed the eBook from my inventory immediately and explained that I had received it in a bundle of stock for an eBook site.
So the old phrase, "caveat emptor" or "buyer beware" raises its head again.
If you find yourself in the same position, just remove the item from sale. Don't bother arguing about it. I still have around 200 products in my store so I'm not going to lose out by having my stock list reduced by one.
(Actually I never sold any copies of the product in question, and I doubt whether I would have sold many in the future)