There are some people that for what ever reason get a rush to screw with a UPS man's job.
I had a woman that would tail me for hours. I even had several customers that I delivered to while she was there. She told them that she just hated that delivery man, and would get him fired if she could.
Those statements from my customers did well at the hearings. Afterward, I had my attorney send her a letter telling her that any more harrassment on her part, with UPS harrassment in return would result in a lawsuit.
UPS did not want me to send that letter, but since they took everything she said as gospel, and tried to give me problems, I had no other choice.
So it happens. Just document what the company does. Then get a good lawyer to send the letter to the woman. And then sue her if she does not back off.