The scheme involved rigging handheld payment terminals to steal the account details and PIN numbers of hundreds of people in New Zealand.
Chea Sina, Kevin Roberto Flores Roldan, Mario Rivera and William Alexander Rivera-Rivas were each convicted of two charges — one for being part of an organized criminal group and a second for fraud.
The four men pleaded guilty to the charges in November.
The court was told the group arrived in New Zealand last March with the sole purpose of defrauding banks of as much money as possible.
Judge Phil Gottis said they quickly set about stealing 27 handheld terminals from shops in Auckland and Hamilton in the period between March 17 and April 5.
They modified the machines, put them back, and then skimmed the data from people's bank accounts, stealing more than $562,000 from about 200 people.
The account information and PIN number were sent to other members of the operation in Canada, who cloned the cards and withdrew cash from ATMs there. None of the stolen money has been recovered.
"The offending was hot and strong and going very quickly after you got to this country, and within a very short space of time 23 stores were targeted and large amount of money was stolen," Judge Gottis said in handing down the sentence.
Defence lawyers for the four argued for a lower sentence, saying their clients had been driven to the crime out of desperation for money and regretted a terrible life decision.
Lorraine Smith, who was acting for Cambodian-born Sina, said her client's family was killed in the war and he had gone to Canada as a refugee.
Judge Gottis took into account the group's guilty pleas and remorse, but he said the crime was pre-meditated, the operation sophisticated, and the gravity of the offense needed to be reflected in a strong sentence.
"There can be no question that people who come here deliberately to defraud the banking system in that way or any other way need to be dealt with with some severity by the court. A sentence which properly denounces that conduct and deters others who may be minded to embark upon such a process must be put in place," he said.
The four arrived at Wellington airport separately last year with equipment for modifying the EFTPOS terminals in their luggage. The suspicions of customs officials were raised, and some of the equipment was confiscated.
But more tampering devices were sent over from Canada.
Det. Sgt. Russ Bagley says the police, customs and the financial sector worked together to monitor the group and track them down. He also said that New Zealand isn't a soft target, and skimming crime here is much lower than in other countries.
"I think the court today has sent a clear message to these international criminals who come to New Zealand, that if they do they get caught then they are going to face severe custodial sentences for sure," he said.
Judge Gottis said various banks lost money and the company that owned the machines chose to replace all similar models, spending between $840,000 to $1,700,000.
He said that because the stolen money was withdrawn overseas and none of the four men had any of it, it would be fruitless to try and seek reparation.