In September 2022, nearly 10 million Australians had their data compromised when telecommunications giant Optus fell victim to a data breach and 10,000 customers had their driving licences, passports and Medicare details leaked online.
The incident drew condemnation from politicians and the public and official complaints grew.
A report from the Australian Communications and Media Authority (ACMA) found the number of complaints received by telecommunications companies had increased by 2.3 per cent to more than one million in the 2022/23 financial year.
ACMA chair Nerida O'Loughlin says one million complaints is far too many and telcos must do more.
While it was unable to confirm whether that was driven by the Optus data breach, a separate report from the Telecommunication Industry Ombudsman (TIO) found complaints to the company increased by almost 30 per cent compared with the previous financial year.
Vodafone and Southern Phone also recorded an increase while Telstra had a 36 per cent drop in complaints.
ACMA chair Nerida O'Loughlin said telecommunications providers needed to do more for consumers.
"A million complaints is still far too many," she said.
"People rely on their telecommunications services to access work, education, health, government services and keep connected.
"Consumers are still experiencing too many issues."
Telstra bucked the trend and had a 36 per cent drop in complaints in the 2022/23 financial year.
There were surges in complaints about poor customer service, failure to cancel a service and inconvenience.
With the cost-of-living crisis weighing on Australians, complaints relating to financial hardship also increased, making up nearly half of the TIO's overall complaints.
Victorians accounted for the highest number of financial hardship complaints, which increased seven per cent.
Ombudsman Cynthia Gebert said providers needed to better assist their clients.
"Telcos need to make sure they are offering flexible payment methods and specialised help and support for people who are struggling to pay," she said.
However, complaints from phone and internet consumers decreased generally by 16.5 per cent while mobile phone service complaints remained steady.