I am 21 years old and have these friends who went to school with me. They were my classmates back then. We were close during our school days, but departed in our own ways once the school was over. We joined different colleges and spent 4 years studying during which none of them kept in touch with me.
After the college got over, I got a call from an unknown number, mocking my family and their profession. I straight away recognized that it was them, because only they knew about my parents and their jobs. Also, I was able to tell because of their distinctive voices. I wrote it off, and casually asked how were they doing. Out of the blue, one of them (It was a conference call) went on to ask whether my X (my dearest family member) was still alive (in a mocking tone).
I went numb and couldn't utter a word. My "friend" kept on mocking asking the same thing. When I told X is fine, he asked why is X still alive, and that X should die. He had never met X so I'm guessing he has nothing against X but just to mock me and sound cool with other friends.
I even tried telling my friend that such an act is totally not cool and that I don't appreciate it, but he asked me to go f**k myself up.
The good news is that I live in a different city but they live in my home city, where my family lives, so whenever I go to my hometown, I might face them.
I feel like I may want to keep in touch with them because they could be just doing it for fun, but I am deeply hurt. I hope they recognize their mistake. How should I tell them so?