{{{{{HUGS}}}}}
I just got home from chaperoning a band trip and read your post. It's bad enough to have to fire someone, but to have them keep calling you.......I can only imagine how that makes you feel. It really stinks that your company can't do more to make sure you are safe. Do you have security guards? If so, it looks like they could make them aware of the situation, so they could stop him if he shows up. Hopefully, the guy will think twice before calling your home again. I think your DH did the right thing by telling him off.
Stay safe and hopefully have a good weekend and a better week next week.