The ongoing coverage failures frustrating Telecom mobile customers in Wanaka is having a positive spin-off for rival network Vodafone.
Sales of Vodafone prepay Sim cards in Wanaka have risen in recent days as Telecom customers continue to experience heavy congestion caused by a huge influx of visitors to the area.
Vodafone New Zealand spokeswoman Emma Carter said staff in the Wanaka store had reported customers attributing their switch to issues with network congestion: ''They simply haven't been able to use their smartphones or tablets reliably.''
Last summer, Vodafone suffered the backlash when the annual population spike overloaded its network. It subsequently quadrupled its capacity.
Angry comments on Telecom's Facebook page describe the coverage in Wanaka as ''virtually non-existent'' and the network as being ''unusable''.
Land Search and Rescue member Davie Robinson was concerned the organisation would not be able to contact him for help in an emergency.
''It's one of the busiest times of the year in the hills here. How many other team members are in the same position? ''The yearly influx of folk to Wanaka for new years is completely 100% anticipated. You have failed to provide the service that we pay for,'' Quentin Smith wrote.
Telecom media and public relations manager Lucy Fullarton said the increase in ''data-heavy applications'' like social media was unprecedented.
Congestion problems had improved yesterday, Mrs Fullarton said.
It had ''tweaked'' the network to try to provide some immediate results and was continuing to work on long-term solutions.
Mrs Fullarton encouraged customers to use Telecom's free Wifi hotspots in the interim.
Compensation would be considered on a case-by-case basis, she said.
