A Singapore court on Wednesday issued jail terms to four employees in an electronics shop that cheated many foreign visitors, including one Vietnamese who bought an iPhone 6 there last year, according to Singaporean news websiteChannel News Asia.

The four defendants who worked for a Mobile Air shop in the Sim Lim Square trade center were sentenced to four to 14 months in prison on charges of cheating.

Koh Guan Seng, 38, was condemned to 14 months in jail, Kam Kok Keong, 31, to 11 months, Kelvin Lim Zhi Wei, 32, to four months, and Lim Hong Ching, 34, to six months, Channel News Asiareported.

According to the prosecution, the four defendants were hired by Jover Chew Chiew Loon, 33, as salespersons in the Mobile Air shop.

Chew, the shop owner, coached the four men to cheat unsuspecting customers in exchange for a 40 percent commission on the profits made from their sales, which amounted to 16,149 Singaporean dollars, all made using unscrupulous sales tactics from April to October 2014, Channel News Asia said.

At the court, deputy prosecutor Eunice Loh recommended severe penalties as a deterrent to those who intend to perform similar frauds in the future, Singaporean media reported.

Singaporeans took notice of the fraudulent behavior of the Mobile Air store in October last year after the shop paid back 1,010 Singaporean dollars to a customer in coins.

A month later, Vietnamese tourist Nguyen Van Thoai went there to buy an iPhone 6, and was cheated.

Thoai, 28, was asked by Mobile Air Pty Ltd in Sim Lim Square to sign an invoice in English, a language Thoai barely understands.

This obliged him to pay an additional S$1,500 for a 1-year warranty, which upon realizing sent him to his knees, begging in vain for the store to return him his money. He eventually left the shop with S$550 poorer, and with no iPhone 6.

In November last year, Thoai told a Chinese-language Singaporean newspaper, Lianhe Zaobao, that he had bought a new iPhone 6 with the money he received from a Singaporean businessman, and will not receive any further assistance.

"I've been cheated $550, so I'll only get $550 from a kind person, and I will receive no more. I am grateful for your kindness, but I just want to get the same amount I lost," Thoai told the newspaper.

It is expected that the trial for the shop owner, Jover Chew, who faces a total of 28 charges, will take place on October 28.