Three words: Class action suit!!
I have wanted to be a published writer all of my life.
During my first years of using livejournal, over half a decade ago, I naively would share personal writing, (with rights info stated clearly). Still it was livejournal, not a website, publication, etc.
I was very popular back then online, I 'managed' and led 3 gigantic livejournal groups, an international occult community, and was a regular and well-read blogger of arts and musical happenings.
Amoung my friends list were several publishers, editors, writers, and celebrity artists, including one of the main editors of this country's leading and most widely read science fiction magazines. This individual added me, but was constantly passive aggressively snubbing me in personal posts. I, as always, was kind and dismissive, not taking his issues personally. Eventually, this man copy pasted 90% of a work I posted in my private journal, and announced, publicly, that this was his very first personal writing that he was going to have published, and asked for his audience to offer their opinions. It was my work, word for word, with his own intro and ending added on. In the first five minutes, 184 fans commented that his work was genius, marvelous, amazing, inspiring, and that he was a gifted writer who definitely needed to be published immediately and stop hiding behind his editorial mask, and that they would support him and purchase his writing when published.
I was crushed.
I couldn't sleep for weeks.
It was emotionally devastating.
I was suffering from a serious illness at the time, and that event put me in the emergency room, just from the resulting physical toil of the upset.
I pulled all of my work off the net and never posted any personal work online again. Your story is somewhat different than mine, but it reminded me of how horrible that experience was, to feel helpless because someone with more power than you decides to steal your words and work, make you feel like you are too small and insignificant to have rights or to defend ownership of the work, and you have no recourse. I hope if anyone reading this who's ever doubted that stealing other people's work has no real harmful consequences has a change of mind and heart. Plagiarism is not only illegal, it is an attack, it is harmful, it's a personal violation, and we don't do near enough in this country to penalize copyright violators.
I seriously hope you gather everyone who's been ripped off by these ruthless pirates and form a class action suit to put them out of business for good.
Good luck to you!