First of all: Thanks to all of you who helped me with this problem. Being a newbie (wet behind ears, green, whatever) in self-publishing business I needed to learn the right terms like DMCA, copyright infringement, etc. - and the ways accessing the problem.
It wasn't about the money: My works are and will be freely available here at SOL, I owe that much to this community - It was more like setting a limit, or a principle. This is MY work and it's up to me to decide how it's made available. Most likely my commissions from Amazon will never let me give up my work - unless someone decides to make a Hollywood -production out of my story ;) Well, probably not even then.
For those interested, I can tell the steps that I did:
- Immediately I contacted LargePDF.com via their own DMCA form. Despite promises on the pages, nothing happened and there was no response.
- Contacted Amazon - but most likely not the correct place or then they just didn't care as LargePDF.com wasn't running inside AWS.
- Used an IP location service to figure out their ISP, which was in this case Cloudflare, Inc. Made an abuse report (DMCA) to them about LargePDF.com
--> They responded, that they are only offering a reverse proxy, pass-through security service - but they also forwarded my report to the responsible hosting provider, which was www.worldstream.nl, abuse contact being: abuse@worldstream.nl
- I sent the mail I had kept on sending also to them.
This far there hasn't been any response neither from LargePDF nor WorldStream - but the important thing is that the story was removed from the service. Maybe it would have been easier just not to care, since the thing just pissed me off and took away some of own time that I would have liked to use for writing.