More than a dozen groups have set up pages on the social networking site Facebook to vent their anger at Telecom over its XT mobile network crash.
Thousands of disgruntled customers have joined the intenet sites.
A breakdown at about 11am on Wednesday affected tens of thousands of customers south of Taupo, and while the majority were reconnected that evening, thousands in the lower South Island remained without service. The network was restored by 10pm on Friday.
Telecom says a review will be ordered to find out what caused the problems and a compensation deal will be announced.
Jordan Mauger of Christchurch, who has set up a Facebook group, says the heat is on Telecom to devise a fair system where customers are adequately compensated.
The Government has said compensation may be appropriate following the latest network failure.
The company's chief executive, Paul Reynolds, says the fault has been unacceptable for customers and compensation will be announced early next week.
Customers advised to reset mobiles
Telecom is urging customers who are still having problems following the crash to reset their phones.
The company says in many cases the issues can be resolved by removing the phone battery and sim card, then putting them back in and switching the phone on again.
Spokesperson Mark Watts says Telecom will be enlisting the help of an international company to review why the network failed and how a repeat can be avoided.
The chief executive of marketing firm BrandNew, Dave Bassett, says the XT crash will affect the reputation of all Telecom's products and services and make it difficult for the company to portray itself as a leading edge communications provider.
Telecom's competitors Vodafone and 2degrees have reported a surge in sales and inquiries, but Mr Bassett says it's unlikely there will be a mass movement of customers away from Telecom because of the time and effort involved in changing companies.