He owed $21,000, but was asked to pay $33,000.
The reason for the extra $12,000?
"The debt collectors said it's their 'salary'," said Mr Sherman Chang, 53, the owner of a Chinese soup stall at a foodcourt in Funan DigitaLife Mall.
"When I asked why I had to pay extra when I wasn't the one who employed them, they wouldn't explain.
"But they said they would keep coming after me if I refused."
Mr Chang had originally owed his supplier $21,000, but the two parties could not agree on how or when the debt would be paid. The supplier then engaged debt collectors from Double Ace Associates.
On Jan 15, six collectors from the agency reportedly caused a ruckus when they turned up at the mall's foodcourt during lunchtime to demand payment.
Mr Chang claimed that the collectors damaged items at his stall, and even smashed the cash register in an attempt to get money.
"They chased our customers away and threw everything on the floor," he told The New Paper last week.
"Money that I owe, I have to pay back, I will definitely pay it back. But why should I pay the debt collectors when I didn't engage them?"