I rang back the number (03) 9912 4803 once but got disconnected

Has called quite a a few times. Left a message just " hello" from a man's voice. No idea who this is. Not interested to opening up opportunities to be scammed or harassed when I don't know this person.

They have called from the same place constantly over the last 4 days from 6am to 8pm from a group of associated numbers.

(03) 9912 4800

(03) 9912 4801

(03) 9912 4803

(03) 9912 4805

(03) 9912 4807

(03) 9912 4808

(03) 9912 4809


When I have answered at least four times, they have hung up on me.
I then get “No caller Id calls”

rang twice today and hung up when I answered. Have now blocked