Lengthy delays in connecting to the National Broadband Network (NBN) made up most of the NBN-related complaints to the Telecommunications Industry Ombudsman (TIO) in the last financial year.
The TIO announced in its annual report on Wednesday that there were 3,982 NBN-related complaints during the 2013-14 financial year, with close to 2,000 customers reporting delays in connection, and over 500 complaints about missed appointments.
TIO Simon Cohen said that the number of complaints related to the NBN increased each quarter.
"This is predictable, given an increased rollout of the National Broadband Network," Cohen said. "A theme in these complaints has been communication breakdown, with consumers often reporting that they don't know who to turn to solve their problem."
A total of 18 percent of all TIO investigations were related to the NBN, he said, and the TIO has established a team specifically focused on the NBN to work with service providers and NBN Co to resolve issues.
The complaints weren't easy to resolve, either, Cohen said.
"Resolving these complaints often takes time, and it can prove very difficult to put connections back on track when something goes wrong," Cohen said.
This time last year, Cohen said that there were very limited issues with the NBN. However, some industry representatives have previously indicated to ZDNet that their companies faced complaints to the TIO based on missed appointments from NBN Co to connect the NBN.
iiNet held out on signing its wholesale agreement with NBN Co, in part because it was still liable for paying for NBN Co missing booked appointments.
ZDNet understands that many complaints also come from customers who believe they can connect to the NBN, but haven't had their premises made ready for service.
A spokesperson for NBN Co said that the number of complaints demonstrated the complexity inherent in the NBN rollout.
"The TIO report just demonstrates the complexities inherent in the original rollout model, which involved sending workmen down every street, onto every nature strip, and into every home in the country to install new equipment," he said.
"[CEO] Bill Morrow's key focus is improving the customer experience and getting families connected. We're working to make more fibre homes serviceable. We're also moving to a new model that uses the existing line into the home. It's a far less invasive process, and will make it much simpler and quicker for people to connect."