A 17-year-old teenager siphoned off S$15,240.59 from the Decathlon branch in Chai Chee while working there part-time as a cashier.

He took advantage of a flaw in the point-of-sale system to make fake refunds to himself.

Thinesh Paramasivam, who is now 20 and serving National Service, pleaded guilty on Wednesday, Sept. 18 to two charges of misusing the system to perform 88 fake refund transactions over close to two years.

Thinesh's actions constituted offences under the Computer Misuse and Cybersecurity Act, which carry a jail term of up to three years, a fine of up to S$10,000, or both.

Court proceedings have been reported by Today.

How he pulled scam off

The fake refunds took place between June 10, 2016 and Feb. 24, 2018.

It started soon after Thinesh joined Decathlon as a part-time cashier.

He discovered that creating fake refunds would channel credit from the point-of-sale system to his own bank account.

All he had to do was to indicate in the system that certain items were to be refunded -- even though none eventually were returned and no actual customer sought a refund.

Refund amount increased over time

Thinesh took S$136.49 during his first fake refund on June 10, 2016.

On Oct. 4, 2016, he again made a fake refund for a S$3.08 item.

The amount for fake refunds grew to as much as S$305.60. 

To circumvent the surveillance cameras in the store, Thinesh would at times use a sheet of paper to shield the terminal.

He would also take cash directly from the cashier’s terminal instead of channeling the money into his bank account.

How Decathlon discovered the missing money

Decathlon only discovered the fake transactions in February 2018 after finding discrepancies in its inventory system. 

The system indicated items were refunded but there were no corresponding products returned.

A store manager then lodged a police report.

The report stated that two staff members at Decathlon had “stolen money” from the company. 

Could be suitable for probation sentence

A pre-sentencing report was called by the district judge.

It would assess Thinesh’s suitability for a probation sentence.

He was under 21 years old and a student at the time he committed the offences.

The deputy public prosecutor requested for a report assessing if Thinesh would be suitable to be sent for reformative training, but it was declined by the district judge.

This was after the judge heard it might disrupt Thinesh's National Service obligations.

Reformative training, which puts the youth offender through a comprehensive programme in a closed and structured environment, is different from probation.

Reformative training results in a criminal record, while probation does not.

Thinesh will be sentenced back in court on Oct. 30.

He remains out on a S$5,000 bail.

Another culprit

The case also involved another cashier, a 21-year-old woman who was Thinesh’s secondary school classmate. 

Thinesh admitted to having told her about the loophole.

Her case will be heard at a later date.