The Telecommunications Industry Ombudsman has reported a 96 percent rise in complaints lodged against Vodafone in the second half of last year.
About 5,370 new Vodafone complaints were received by the TIO, mostly for "mobile telephone coverage issues, long wait times, failing to act on promises and not being able to contact Vodafone at all".
Vodafone suffered well-documented problems with its network in the latter half of last year, leading to a major class action by disgruntled customers wanting compensation or out of their contracts.
However, the carrier also blamed crafty customers looking for a free iPhone 4 upgrade for a rise in complaints in around September last year.
“Customer frustration with Vodafone is understandable,” the Ombudsman Simon Cohen said.
"It is one thing to have a service problem. But what is particularly concerning is when consumers cannot contact someone to have their problems sorted out.”
The sharp rise in complaints against Vodafone helped fuel an overall 9 percent rise in new complaints across the telecommunications industry, which Cohen described as "extremely disappointing" given a general downward trend in recent months.
The rise in complaints had "mostly been driven by a 20 percent increase in mobile phone service issues," Cohen said.
Vodafone chief Nigel Dews said in a brief statement that the telco had "more work to do" to keep complaint numbers down.
He pointed to initiatives such as 300 new customer service staff hires and planned network improvements as ways the telco was working to address complaints about its network.