Have a look under "Call blockers" on ebay. They are available for around $60.00. You can simply list all the numbers you want to have blocked. Some models can hold up to 1500 numbers. Maybe that is the answer. I have not tried one as yet but i will be very soon. In the meantime i just lift the handset briefly and hang up. At least that way they have to pay for the call. To do the above, you must have call number display.

i wish these people would leave me alone

Just called them back - they're an organisation called Thought World and they market fuel cards. I got onto their 'receptionist' Donna who at first told me that the Director was unavailable and then confirmed she is a 3rd party answering service for the business and could not transfer me to anyone and only take a message.

Searches on the Internet revealed the following - all of which is publicly available information:

http://www.thoughtworld.com.au/
ABN: 82 131 980 777 - Thought World Pty Ltd
Registered Address: 744 Bourke Street, Docklands VIC 3008
Principal Place of Business: "G01", 499 Punt Road, Richmond VIC 3121
Director: Chetan Saligrama
Address: Unit 12, 70 Edgar Street, Glen Iris Vic 3146
Born: 12/03/1979, Hassan, India
Clients: Motorpass Australia, Australian Power and Gas

I will be writing to the company, their clients, their director, consumer affairs and ASIC in relation to their business practices which breach the Australian Consumer Law and the Do Not Call Register. I would suggest the rest of you do the same.

trying to sell my business some power, using an autodialler by the looks, getting the calls daily for the last few weeks

It's one of those "I would like to speak to the person in charge of the electricity account" tools. If you answer as a business they will not hang up. So annoying, when I am actually trying to do real work

Your phone Company employ's people to call numbers then hang up knowing that most people will call back and when they do they are charged for the call. Next time they will use a different number. It's a "business" racket. If it annoy's you too much call your local member for parliment and tell them to do something about it and get them to report back to you with their findings. That is their duty as public servants and also if they want your vote at the next elections.

I tried to call them back, they do not answer

No answer when trying to call back

Same here, did not answer this as I was travelling on the M5 sydney and number does not answer.

Tried to call back disconect on answer

I tried to call them back 5 times , they do not answer

Receive numerous calls from this number, they hang up on answer