Complaints about telcos' phone and internet services surged by 34 percent in the last half of 2016, according to the Telecommunications Industry Ombudsman.
It today reported 65,970 complaints were lodged between July 1 and December 31 last year, compared to 49,318 in the same period of 2015.
Internet service issues represented 37 percent of total complaints, and grew a staggering 54 percent in the half.
Close behind were mobile phone complaints, taking up 35 percent of all reported problems. Growth in mobile issues was at 19 percent.
Landline complaints also grew 32 percent to represent 27 percent of the total number of reported problems.
Most of the reported issues with phone and internet services involved customer service, billing and payments, and complaint handling, the TIO said.
It pointed out that it only captures complaints that have been lodged after attempts to address an issue directly with a telco have failed.
The Communications Alliance attributed the rise to the scaling NBN rollout and the "additional implementation challenges" it brings.
Complaints about NBN services were up just under 7 percent on the second half of 2016 compared to the first six months of the year - reaching a total of 7512 reported issues - and a whopping 117 percent on the same period of 2015.
However, the number of premises connected to the network in that time grew almost 225 percent, the TIO said, making the rate of increase for complaints less than the rate of rollout growth.
NBN Co said the TIO did not distinguish between complaints made about the NBN network and those of a retail services provider offering an NBN service.
It claimed the results showed "progress" by NBN Co and RSPs in reducing the number of TIO complaints about the NBN.
Comms Alliance CEO John Stanton said the TIO results made it clear the wider telco industry needed to work harder to combat the increased numbers of complaints.
“We have seen five years of falling complaint levels as a result of concerted industry action — dropping complaint volumes by close to 50 per cent — so the recent setbacks reported by the TIO are a matter of serious concern and are being addressed," he said.