Fs.com are a well regarded company. The OP should contact them and see if there's a recall on those cables or something. Sounds similar to what happened with some mains power cables sold by a hardware store in Australia.
FS provides account managers and they are very useful if you are working on a project as they can guide you and help you.
I have a Newegg business account (and maybe a few more for other pc stores, I'd have to check), but I literally never have them trying to get me to buy things. /shrug
Just decline politely. They are not a bad company in that regard.
I have my issues with FS product itself, as it can be spotty sometimes in terms of compatibility and repeatability (e.g. getting the same optics firmware every time over the course of a couple years) but they typically handle exceptions and problems quite well. Via your account manager contact.
Weird reason to hate a company, imo. Would be far different if they continued to spam you with phone calls/e-mails after you declined the request.
Sounds like both parties dodged a bullet.