My first book was published through Xlibris. They have reported no sales from numerous authors, so no one is receiving royalty checks. They are ignoring my calls and emails, to get back my original work. I would like for a new company to publish the book. Can I legally take my book to a new company for printing? Can I just change the cover, since my kids did the artwork for the interior? I do not know what I need in addition to an ISBN for each book. Is a UPC necessary? What else is mandatory? Any help is greatly appreciated, as I have 3 series to get into print and refuse to let Xlibris touch them.