Yet in just one day of June this year she bought almost 20 worth more than $1800, and all to pay for what she thought was her National Broadband Network connection.

Olimpia, who has asked for her surname not to be used, had never heard of the now-popular scam method, which tricks consumers into paying for fake essential services or fines by purchasing iTunes gift cards.

It is knowledge she now wishes she had when she answered her phone to a man purporting to be from "NBN Co," offering an internet deal that would see her connected within three days.

"I told him I hadn't received any information in the post that NBN was being rolled out in my area soon, but he said he was an NBN wholesaler and that I needed to be connected or I would no longer have internet."

Despite some doubts, Olimpia agreed to make the required upfront payment to cover the next 18 months, by purchasing $1800 worth of iTunes vouchers, $900 each for her personal and home office internet.

The Melbourne resident is one of 316 Australians to have been targeted by scammers impersonating NBN this year, according to the Australia Competition and Consumer Commission's Scamwatch.

Just 20 Australians have reported combined losses of almost $28,000 this year alone, while the remainder have been targeted for personal information, such as driver's licence, passport and Medicare numbers.

"Scammers are looking for your money, but almost as much they are looking for your personal information," said ACCC deputy chairwoman Delia Rickard.

"They are increasingly using trusted government brands like NBN to trick people into falling for scams."

Among the most common NBN-related scams reported to Scamwatch are fake account scams, in which a victim is offered a low price to connect to the NBN, often by paying through gift cards.

Remote access scams are also commonly used, in which a scammer pretends to be from NBN and calls to alert a victim to problems with their computer, as well as phishing scams, in which scammers impersonating NBN will call to trick victims into handing over valuable personal information.

As with most scams, Australians over the age of 65 are among the most vulnerable.

"NBN will never phone you out of the blue to try to sign you up to a service over its network. NBN is a wholesaler, meaning they don't sell direct to the public. If you get an unsolicited call like this, it's a big red flag that you're dealing with a scammer," Ms Rickard said.

She added that if any person or organisation asked for payment through iTunes gift cards it was "100 per cent a scam".

For Olimpia, by the time she realised it was a scam it was too late, as she had already purchased and sent the voucher codes of the iTunes gift cards.

"I'd heard about scammers pretending to be the Australian Tax Office via emails, but I was definitely not aware of this, or iTunes voucher scams."

She said she placed her faith in the caller because two weeks prior she had registered for updates about her local area on the official NBN website.

Last month a 74-year-old Melbourne woman was swindled out of $46,000 by a scammer who groomed her to buy 330 iTunes gift cards.

The scam figures come as the consumer watchdog released new guidelines for internet providers advertising National Broadband Network speeds.

The guidelines include providing consumers with typical peak evening speeds, adopting standardised labelling of peak evening speeds and offering customers discounts or refunds if they cannot get the speeds they expect.