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

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!

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

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

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