Many customers said they were considering changing to another telco.
Vodafone head of customer care Fiona Harnett said calls about straightforward customer concerns would be outsourced, while the retained New Zealand staff would deal with complex technical issues.
"We are investing significantly in simplifying our customer systems and processes, supporting customers to use self-service tools, and using our service centre in the Philippines to handle more simple customer requests such as top-ups, account balance inquiries, etcetera.
"As part of the proposed structural changes, we will be focusing our New Zealand-based customer care teams on improving the handling and resolution time for more complex technical calls."
She said customer care staff handled hundreds of thousands of calls monthly and this month, more than 70 per cent of calls had been answered in 10 minutes or less and more than half had been answered in less than three minutes.
"We understand how frustrating it can be to wait to talk to us, and we apologise to those customers who have been affected. We can do better and we will."
The job cuts - which include team leaders, contractors, technology and "resolve" positions - would start by the end of this month, the Vodafone document said.
It also said that if its plan went ahead, 90 per cent of prepay and half of on-account customer calls would be handled in the Philippines by call centre operator Teleperformance.
The chief executive of the Telecommunications Users Association, Craig Young, said he was always concerned when providers downsized "But consumers will make a choice and if they end up getting bad service from one supplier then they've got plenty of others to go to."
Hour's wait for an answer
"What Vodafone is now indicating ... is that they want your business but have absolutely no intention of providing after sales service."
Dave Barlow
"By phone it is just about impossible to contact them, so I use email which has a far better contact rate."
Allan Shearer
"I had to wait for over 20 minutes for the call to be answered and on the second occasion it took over an hour ... before I received only a partly satisfactory answer."
Campbell Murray
"I was with Vodafone for many, many years. I got my first mobile from them, the old brick style. I left them in November as they are impossible to contact with issues."
Yves Moretensen
"I waited for 45 minutes each time on two different days for customer services and no one answered my call. I can't believe they think they can cut the service further."
Laurence Thorogood
"Customer service at Vodafone is fantastic ... it is a sad day to hear they will dropping staff. Will end up like Spark, talking to a machine I guess."
Hellen Fox