Telecom companies are the worst offenders when it comes to contacting people on the Australian Do Not Call Register - and are responsible for more than half of the complaints about unsolicited calls.
The Australian Communications and Media Authority (ACMA) said 55% of complaints were based on calls from telecom service providers.
"Consumers register their telephone numbers because they want to reduce the number of telemarketing calls they receive and it is unacceptable to see that some telcos are not respecting that decision," said ACMA chairman Chris Chapman.
"Businesses have had ample time to adjust to the new laws and by now should have robust compliance measures in place."
ACMA had issued four infringement notices to operators in the past 12 months, Chapman said. In October, ISP Dodo was fined A$147,400 ($97,400) for violations of the register.
"ACMA will continue to seek an environment of accountability in the telecommunications industry when it comes to Do Not Call compliance," he said.
The regulator has launched a campaign to improve compliance among operators. These include investigations, warnings and launching an industry-specific newsletter.