How do I stop my former employer from openly discussing events that led to my dismissal?

I was let go, due to a mistake I made. I did not expect the company to keep me on board but they did. Someone higher up in the company pushed and pushed for me to be let go. Now I have proof that this employer is openly telling my ex-colleagues the events that led to my dismissal: asking people personal questions about me, where I live, if I am still with my fiance who was involved with the reasons I was let go. There are multiple managers who are discussing my case to other employees. Am I protected? Should they be talking about the reasons I was let go to all other employees? Isn't my personal information regarding me being let go private? Can I contact HR and make them aware of the situation? I do agree that I should have been let go, I do not want my job back with this company, I only want them to stop talking about my issue to other employees as it may affect me ever getting hired again elsewhere. What can I do?