Security not Taking Threatening Behaviour Seriousl

I called security and anonymously reported people who were making excessive noise (against the rules) and loitering in the corridors (against the rules). The security came over and let them know that I was the one who made the complaint by knocking on my door. I did not open as I was afraid for my safety. The security left and they continued making noise and loitering in the corridors while knocking on my door and yelling abusive statements about me and threatening to hurt me and damage my car. I called security again to report the threats and he again insisted that I confront them. I said that I would not and he stepped outside and continued talking with them. After he left they continued standing on the corridors making abusive statement.