<human>: Can you succinctly summarize the text in 1-3 sentences?

Background: I work at a group home for adults with mental illness. Everyone is very high-functioning; I only have face to face contact with each resident about 1 hour a week.  I try to set very strict rules about when it is and is not acceptable to call my cell phone outside of working hours (M-F, 9-5).  Despite my best efforts, some of them still call me for non-emergencies outside of work.

My question is, how do I politely remind them of this rule (no calling my cell phone after five/before 9/on weekends unless it's an emergency) when they call me? I've tried several ways, and haven't found a way that doesn't come off SUPER bitchy, and with a population that is sometimes more sensitive to social cues than others, I have to tread especially carefully.
<bot>: How to I nicely (and professionally) tell someone to fuck off when they call me about their roommate using their towel at 5 am?