Is it required for section 8 housing to keep apartments available in case of emergency services?

I am trying to get in section 8 housing due to violence. My name has been on the list for 2 years and the police dept has sent a letter on my behalf. I thought that emergency services were supposed to be available in regards to situations regarding this; however, the person in charge of these particular apartments informed me that there weren't any openings. Please tell me what my rights are