Millions of Australians are still being billed for calls to 1800 numbers after a group of 13 companies, including telecommunications giant Vodafone, missed the January 1 cut-off to make mobile calls to those numbers free of charge.
The industry set its own deadline to implement the changes in July 2014.
Many essential service providers including Centrelink, Medicare, and the Domestic Violence Crisis Line, as well as drug, alcohol, and mental health support services, use 1800 numbers to encourage callers to contact them for free.
Australian Communications Consumer Action Network (ACCAN) chief executive Teresa Corbin said it is unfair that some Australians are still paying for mobile calls to 1800 numbers.
"Recent statistics show that consumers are increasingly reliant on mobile phones for communicating.
"Now that mobiles are the dominant form of communication, we're just asking that these free calls be extended to mobile."
The Australian Communications Consumer Action Network said that some customers with Vodafone are being charged 98 cents per minute for calls to a 1800 number, plus an extra 40-cent connection fee. This means a two-minute call would cost AU$2.36.
Vodafone had an estimated 5.2 million mobile phone customers in July 2014, accounting for 17 percent of the mobile phone market in Australia.
A Vodafone spokeswoman told AAP that customers wouldn't pay out of pocket for 1800 calls until they exceed the cap on their plan.
"We're confident that Vodafone offers market-leading plans that meet a broad range of customer needs," the company said in a statement to AAP.
Financial Counselling Australia executive director Fiona Guthrie said it is hugely concerning that some Australians cannot afford to ring for help.
"The cost of calling a 1800 number from a mobile is really prohibitive for many low-income consumers," Guthrie said.
The full list of companies that failed to meet the deadline were Vodafone, TPG, Dodo, Vaya, Yatango, Cmobile, Live Connected, Bendigo Bank Telco, Hello Mobile, GoTalk, Lebara Mobile, and Aldi Mobile.
As of June 2014, Australia had 31.01 million mobile voice and data services in operation. There are roughly 115,000 different 1800 numbers.
Updated at 9.36am AEDST, February 19: ACCAN issued a correction on February 19 stating that Jeenee Mobile, which was included in its original list of companies that had failed to meet the deadline, has in fact honoured its commitment to deliver free calls to 1800 numbers for its mobile customers.