Have had this a few times as well.
If you are on the DNC register, probably still come through as (02) 8004 3554 is probably a spoofing call from overseas.
DNC may not be able to stop them. I just keep blocking numbers like this.

Caller: ReachTEL research

Called number back and it said thank you for calling reachTEL research. I hung up

This number has rang several times today, every 30 mins. I finally answered only no one there, they just hung up. I'm on the do not call register but it only works for Australian business not overseas calls.

Has called 3 times, I answered the last one but no one there and they hung up after a few seconds with nothing from their end. No message left nothing, and all calls after 6pm (6:23pm, 7:20pm and 7:46 pm)

Got this call. Silence on the other end then hung up. Scammer or 'random survey'. On the Do Not Call register.

got this one twice today..f***in sick of the random numbers calling me. are you guys on the donotcall register? i only just joined..fml

?? keep getting this one - never leave message

I had it twice today on work mobile. First time no message was left. 2nd time I answered but no one spoke, instead it made funny pulse dialling type noises, like it was connecting to another number or forwarding or something strange. Hung up after 12 seconds. No idea who they are.

?? keep getting this one - never leave message, and can't call number back - always engaged

Damian you should report them for calling you, it is illegal. Go back to the DNC register page and check it out.

got this one twice today..

f***in sick of the random numbers calling me. are you guys on the donotcall register? i only just joined..

fml