Step 3: set 012111234520 on a blacklist
Most mobiles can block particular phone numbers. Please, read your mobile’s manual for further instructions.
After you placed your mobile or residential number on the official Do Not Call Register: telemarketers are legally obliged to delete your number from their database within the next 30 days. Unfortunately, there are some legal loopholes, e. g. market research calls are not considered telemarketing and are therefore still possible. Also phone calls from various institutions, organizations and charities are excluded from the ban. Another downside of the register is that it does not allow placement of small business numbers.
If you are getting telemarketing calls despite being registered, you can pass a complaint to the Australian Communications and Media Authority (ACMA).
Next to getting your number out of the database of call centres etc. there are also possibilities that work the other way around. First of all, you can inform your provider about nuisance calls because there are opportunities to blacklist numbers there. Some phone systems have blocking options as well, please consult the manual for that. Also some applications for mobile phones will help you to know more about the calls you receive and decide beforehand if you will take a call or not.
Although you will never be able to blacklist all scam numbers or know about every deceptive caller, getting yourself informed regularly will certainly help reducing the amount of calls anyhow.