i recieved and missed  a call from this number on my personal mobile phone, when i returned the call to this number a male answered he said hello and i said hello then he hung up on me, i called back and the phone rang out and went to a answering service, i left a stern message

Missed a call from this number (03998289040)to my private mobile number, when I called back a recording said "Optus wishes to advise the mobile number you are calling has been disconnected".. I am still recieving calls from this number which does not look like a mobile number to me.