getting these calls and simular numbers, just the three ending numbers usually differ

For about two weeks I've been receiving calls on my mobile from 9, count 'em, NINE different phone numbers all beginning with (02) 8023xxxx... I've not answered any of them and they never leave a message - except for today, when I had a lot of background noise but no actual person speaking.  I figure if it's important enough they'll leave a message or if I'm really lucky, they'll get sick of calling me!(02) 8023 0165, 80230264, 80230267, 80230295, 80230348, 80230361, 80230373, 80230393, 80230431

I got caller ID so I know who is calling.
1st one was from this # (02) 8023 0165 Call Center .. G Money.
2nd one was from this # (02) 8023 0431 I did not answer it.
3rd one was from this # (02) 8023 0451 I did not answer it.

Rings @ about 12PM and again @ 6PM.

I have also been on the Do Not Call register for at least 5 months and yet today, I have just recieved another call from this number.I will be making a formal complaint through ACMA now

For about two weeks I've been receiving calls on my mobile from 9, count 'em, NINE different phone numbers all beginning with (02) 8023xxxx... I've not answered any of them and they never leave a message - except for today, when I had a lot of background noise but no actual person speaking.  I figure if it's important enough they'll leave a message or if I'm really lucky, they'll get sick of calling me!

(02) 8023 0165, 80230264, 80230267, 80230295, 80230348, 80230361, 80230373, 80230393, 80230431

I get calls from 8023-0451 and other numbers starting with 8023 about 2-3 times a day. Never leave any messages. It's such a nuisance.