Hi there,
I'm a UK based SEO specialist and have previous experience of removing bad backlinks for other clients. I've several tools available to me which can help discover backlinks from across the web and will then contact the websites to request removal.
Unfortunatly, no website can be forced to remove a link and should I get no response to the requests, I can follow up with Google Disavow tool to ensure the links don't have any negative impact on your website.
If you'd like to discuss this in more detail, please feel free to message me or send me a link to your website and I can do a little more research to see how far the problem extends.