Plagiarism

Good morning all. The thing that most of us fear about our work, (not the not being published one) well my fear anyway, is plagiarism. I mentioned some time ago on a post here that my work had been taken and reworked into someone's existing stories, stories that even with her pushing them nobody was interested in their original form. The books were based on sex. This person was a member of the writing group I attend and NOW I KNOW (too late) that it was foolish to allow people access to my book. I was asking, I thought, in a safe environment for a critique of my book. It was finished but in need of polishing and the editing being only part done because of the polishing exercise.

I allowed access through a password protected dropbox file. People agreed to look and she was one who said she didn't have time. (that was said four weeks later) Now she has published a series of books (her earlier works reworked) with my idea as the new lead. I didn't want to try and have her stopped as her writing isn't that good. She has even used my chapter headings and worked them into her her book titles. There is four books now and the latest shows a picture of an integral part of my story on the front cover. I didn't want to take action at first as I was about to submit my work and didn't want anything in the pipeline that would put a potential agent off but now I need to do something. Does anyone know where I start to stop this woman from carrying on and then getting these books removed from sale on Amazon, kindle and there is another one I can't remember. Forgive my punctuation I'm seething and just bashed this out looking for HELP please anyone.

Paul Garside, decidedly not amused