Locals in east Auckland say the loss of their banking services and the relocation of its post shop will isolate the elderly in their community.
Kiwibank in Howick is the latest to shut up shop in a string of closures across the country. The decision follows a move in June to close more than half of Dunedin's joint Kiwibank and New Zealand Post branches.
Pakuranga MP Simeon Brown said locals were up in arms about the move.
"I've had a huge amount of response as I've raised the issue," he said.
"A lot of people are very disappointed."
New Zealand Post is looking for someone to take on its postal services in the area.
Its head of retail, Mark Yanmich, said while this would change how people accessed them, the company had to make the changes in order to operate a commercially-sustainable business.
"Along with still being able to access postal services, this approach works well for our customers, who also often enjoy longer opening hours and more convenient locations," he said.
But banking was on its way out.
Mr Brown said he would be fighting the move.
"Just like postal services are a part of our community, the banking and bill-paying services, in many ways, are as important and needs to be retained in Howick," he said.
"A lot of elderly people can't just jump on the bus."
Mr Brown said he would be meeting with NZ Post next Monday to discuss the issue.
But Geoff Waller from Kiwibank said it would be pulling out of Howick because an increasing number of customers were now accessing banking services in different ways.
"The average customer now uses online, mobile or phone banking one to two times a day and visits a branch one to two times a year," he said.
Those who still wanted to visit a shop could go to Pakuranga or Botany, he added.
In November last year Kiwibank decided to close the Owairaka Post Shop in Auckland due to security concerns after a number of robberies.
The dates for the Kiwibank closure and NZ Post changeover have yet to be finalised.