If you’re an Australian and have difficulties with Telemarketers, there is a register where you can enter your home phone number or or mobile number to stop telemarketers calling you.
This is designed to stop marketing companies, however you will receive calls from Charities, (personally I don’t have a problem with this)
To find out how to register go to: http://www.donotcall.gov.au
Registrations only last for three years from the date you registered. After that your numbers are automatically removed from the Register and you may start receiving telemarketing calls again.