A Melbourne debt collector has unleashed a foul-mouthed tirade in court, after he was fined $15,000 and told he faces a potential five-year industry ban.

Michael John Stanyer was convicted in the Melbourne Magistrates' Court on Thursday for breaching consumer laws, after harassing debtors and calling them names including "dickhead liar" and "pathetic, lying loser".

Moments after Magistrate Tim Greenway imposed a conviction and the fine, it was revealed Stanyer would face an even worse punishment.

The court was told he faced a five-year ban from debt collecting activities.

This was because he breached sections of the Australian Consumer Law and Fair Trading Act which prohibit "undue harassment".

The court heard it was possible for Stanyer to apply to the regulator for leniency, but he told the magistrate he would simply ignore the ban altogether.

"I'll just keep operating," Stanyer told the court.

"The world's f***ed. The whole system's screwed."

Stanyer, who made a living out of chasing people up for money owed, said he would not be paying the debt now hanging over his head.

"I'm broke. I've got no assets. I'm not paying $15,000 … I don't give a f*** anymore," he said.

"If I need to be arrested and thrown in jail for trying to make an income, happy days. That's the government for you. Thanks mate, enjoy your day."

"Thank you very much," Magistrate Greenway replied. "I don't think there's much more we can do here."

Consumer Affairs Victoria said Stanyer's offending occurred between 2021 and 2023 when he rang, texted and emailed nine debtors who each owed between $300 and $10,000.

"I'm going to default you first thing in the morning so there goes your credit rating," Stanyer told one man.

Another man who failed to pay a $7,500 fee was rung 56 times by Stanyer over five months and was threatened about "what's coming".

Debt collector claims he was defending small businesses

Stanyer was charged after several complaints were made about his conduct.

Stanyer defended his actions and said he was working for small businesses who were being ripped off by "the lowest of the low".

"They're criminals who haven't paid their debts. We're trying to collect money for the poor little businesses that are going out the back door because people are not getting paid."

Despite pleading guilty, he said: "I don't believe I've harassed people. I don't believe I've done anything diabolically wrong".

In court hearings earlier this year, Stanyer said he was attending an anger management course and said his business, RMS Collections Pty Ltd, no longer employed the tactics that landed it in trouble.

Stanyer said his profession, which regularly involved being abused by others on the phone, had taken a personal toll.

"Doing this is a prick of a job," he said.

According to Consumer Affairs Victoria's website, it is illegal for debt collectors to make threats, use deception or make misrepresentations. They are also required to leave a private property or residence if asked.

Complaints have also been made about aggressive tactics employed by bigger players, including Telstra and the Australian Tax Office.