Industry leaders and government regulators have rubbished the claims and maintained the infrastructure upgrade was a global necessity that consumers were given ample warning about.
Phone security expert Paul Garbett of E-Phones NZ said perfectly working 4G phones had become useless for standard calling because they relied on the 3G network to make voice calls.
"For the last decade we have been sold phones under the banner of being 4G and expected them to work on the 4G network," Mr Garbett said.
He said many of these devices were actually 4G-LTE, meaning they only used 4G for data and SMS but relied on 3G to make calls and therefore stopped working when the system was switched off.
"Our telecommunications providers have known this fact, and sold those phones anyway without any sort of disclaimer to the unaware public.
"This is a strategy that while reducing costs and increasing phone sales, conflicts with the Fair Trading Act."
They knew these devices would cease to function as phones when 3G was shut down but sold them as phones anyway, Mr Garbett said.
He said telcos sold devices without New Zealand-specific voice-over-LTE settings and suggested providers should have offered software to flash handsets with the necessary firmware to run VoLTE natively.
Mr Garbett is offering a paid data-based calling app but acknowledged users would not be able to contact emergency services through it.
"Seriously, you would need to either use a landline, text emergency services, or use another phone set aside for calling on the normal telephone network," he said.
A Commerce Commission spokesperson said decisions about infrastructure and networks were ultimately commercial choices for operators to make.
The Commission contacted 46 potential suppliers of products which relied on 3G services, to ensure that consumers were not being misled and that adequate disclosure was made regarding the shut down of the 3G networks, the spokesperson said.
A Ministry of Business, Innovation and Employment spokesperson said New Zealand telecommunications providers were not generally able to install the type of update suggested by E-Phones.
"A software update of the type suggested by E-Phones would effectively be a ‘bespoke’ update, which would need to be developed and supplied by the equipment manufacturers themselves, for example Apple or Samsung," the spokesperson said.
Consumer NZ product test journalist Nick Gelling said the telecommunications industry had acted in good faith during the shut-down.
"Any recently sold phone should support 4G calling [VoLTE]. At Consumer NZ we think if you’ve bought a phone that relies on 3G calling since early 2024 and you weren’t told it’d stop working this year, you were sold a phone that’s not fit for purpose," Mr Gelling said.
"You’d be within your rights to ask for a refund or replacement under the Consumer Guarantees Act," he said.
New Zealand Telecommunications Forum chief executive Paul Brislen said 3G was no longer supported by equipment makers around the world and was now at its end of life.
