My parents in NZ received a call from this message. Was faint so could not be understood

I have received a call from this number twice in the last week. I missed the call both times. I tried calling the number but I keep getting a message saying something about Oceana Customer Interactive Services. I am with the Optus network.
http://www.ocis.com.au/  ???

THEY JUST CALLED ME TOO, LUCKILY I DIDN'T ANSWER IT. MUST BE TRYING TO SELL US SOMETHING.

IM WITH OPTUS TOO.

Got a call from this number - A woman with an Indian Accent (i work a lot with countries in the asia pacific region), asking to speak to my father - it also referred to him by his shortened name, however the phone is registered under his name.

*added some info*

got a few calls from (03) 9838 2018 or (02) 8114 3800. when you call (03) 9838 2018, there is always an engaged tone. very annoying.. or if you pick up the phone, they hang up on you.

I have received a call from this number twice in the last week. I missed the call both times. I tried calling the number but I keep getting a message saying something about Oceana Customer Interactive Services. I am with the Optus network.http://www.ocis.com.au/  ???