Its Oceania - a marketing centre for Optus.
Call it back and remove yourself from their list!!

Just rang them back - 'Oceania something or other - outsourced contact centre' so telemarketing junk....

They called my cell today and did not leave a message.

I've received so many missed calls from this number and have no idea what company or service it's coming from.

When I answer, the caller hangs up.

This is the Oceania Contact Centre, they do calls on behalf of Optus.
It an automated system that calls, never leaves an message, as a person only gets on the line if you answer.

The same thing happens to me, the number calls and doesnt leave a message.

Same here.  No one on the other end.  No one answers when I call it.  Tedious.

This is the Oceania Contact Centre, they do calls on behalf of Optus.It an automated system that calls, never leaves an message, as a person only gets on the line if you answer.