As a proportion of the number of telecommunications services in operation, new complaints to the Telecommunications Industry Ombudsman in the April-June quarter dropped to their lowest level since 2007-08
The TIO today unveiled its regular 'complaints in context' report which is released in conjunction with industry body Communications Alliance.
There were on average across all telcos 6.5 complaints per 10,000 services in operation (SIO), down 9.5 on the first quarter of the calendar year.
Optus took the wooden spoon, topping the complaints leaderboard with 8.5 new complaints per SIO, up from 7.3 in the January-March quarter.
Vodafone registered a significant drop from 8.6 to 6.3 complaints, and Telstra dropped from 6.9 to 6 new complaints per 10,000 SIO.
"It's very pleasing to see our customers are even happier with their Vodafone experience, with the ratio of complaints in the April quarter less than one third of that just 18 months before," Vodafone's director of customer service, Errol van Graan, said in a statement.
"We attribute this result to our continued investment in our strong network and customer service operations, our award-winning bill shock initiatives and more simplified products," van Graan said.