What my staff has just passed to me is that there may be as many as 17 to 20 staff, but they aren't totally dedicated to the informal function, so the number of players who would look at any one issue on a regular basis varies.
You asked how long it would take; I think it also depends on the nature of the issue and the degree of responsiveness. Some cases may be fairly cut and dried, while in some cases I think a complainant may come in with a full range of issues. They don't always come in with just one complaint that can be addressed in isolation. There are a lot of grey zones, and a number of issues can overlap. I think a timeline is very difficult and I think resources also factor into it; the agency looks at what it can do in a most expedient fashion with the resources it has.