This is obviously a nuisance call, although it came from the same prefix as those from the suburb in which I live!  When I rang back - intermittently no reply or engaged, so obviously other people are ringing it at the same time as I am!

I received the same.  Tried ringing back but it's unanswered.

Had a missed call from this number.  Rang back from mobile and land line which rang out.

Its Hallett Cove R-12 School, for some reason you call 83921020 for the front office but when the front office call you it shows (08) 8381 4065 at your end

Same as above, rang out also when trying to call back.