I answered phone and did not say anything. Caller just kept saying hello. After a short while he gave up and hung up. No attempt was made to identify himself. My number is on the National Do Not Call Register too.

I listened, heard call centre babbling, I said nothing. No comment from caller. Caller hung up.
Now listed in contacts called Pest .. and have blocked the number.
I have a list of pests, nuisances, do not answers all blocked.
Never hear from them again!

Called back and the message says mailbox full!!

Telemarketer. When I said this number is on the do not call register and asked who she was, she hung up on me.

I called back number (03) 8560 1230 reached voice mail but did not say from what company.