You do realize that just because you send a report it doesn't mean users will get automatically perm banned from the server aye?
It comes down to the proof provided, the severity of the rule breaking and in general the situation of the user getting reported.
You said this was three days ago yes? Some bans are a few hours, some are a few days, some weeks some months. It varies very much. I'm not going to say this cause I doubt it, but who knows, maybe even the report got stacked up between other messages in the inbox.
If you feel uncertain about a report feel free to PM them again for information if they looked into it, or if nothing happens, go to an administrator or other mod?