At 48 years of age, Pamela quit her career as a chef in disgust, vowing never to return to the hospitality industry.

The last straw came in December, when she took a job at Alimentari, a cafe in Collingwood in Melbourne's inner east.

When her first pay was handed over in cash — at nearly $5 per hour below the award rate, and with no payslip — she grew suspicious.

Despite handing over her tax and superannuation details, the next pay packets were the same.

After less than three weeks, Pamela walked out.

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She is now unemployed, with less than $3,000 in her Hostplus superannuation account to show for a 20-year career.

"The majority of the employers just don't pay super," she said.

"At this stage in my life I would have hoped to have owned a house, had a good amount of super, that sort of thing. I don't have any of that."

Alimentari cafe says in the past it paid workers it was trialling in cash. ( ABC News: Danielle Bonica )

The scale of the problem of unpaid super in hospitality is hard to gauge, particularly because so many employers pay some, or all, of their wages in cash.

But Hostplus CEO David Elia said his fund was recovering more than $2 million a month in unpaid contributions from employers.

In the last quarter of 2017, the fund recovered contributions from more than 3,000 employers.

"Small businesses in particular may have some cash flow issues that haven't enabled them to make contributions in that particular period," he said.

"I think we have to call it out. There are some employers out there who simply won't make, or don't make, contributions on behalf of their staff."

Cash culture leaves many without super

The Australian Tax Office is supposed to be the watchdog keeping an eye on whether employers are making their payments into super funds.

But usually, it's employees who have to chase it up.

Chad Parkhill faces a fight to get his unpaid super. ( Supplied: Zora Sanders )

Chad Parkhill is still trying to get $2,500 in unpaid super after his seven months at the Brunswick restaurant and bar, Host Dining.

When Chad decided to approach the Fair Work Ombudsman to pursue his unpaid super, he said the restaurant's co-owner Nedim Rahmanovic told him: "Good luck with that."

Mr Rahmanovic admitted to the ABC that he owed "very small amounts [of superannuation] to a lot" of staff, and "more to others".

"That's something we are trying to get on top of," he said.

He blamed the "extreme pressures of running a small business" for not paying employees their full entitlements.

"It's purely a matter of survival. People are only prepared to spend small amounts on food," he said.

The ABC put questions to Alimentari cafe, asking why Pamela and another employee were paid in cash, at below the award rate, and whether super and tax were ever paid on their wages.

In a statement, cafe co-owner Linda Davis said: "In the past, we paid people in cash while they were trialling with the business, at what we believed were legal trial rates of pay. While this practice may be common in the industry, it is not how we operate today."

Often, hospitality workers don't notice the problem until it's too late.

Jesse Lewis says workers shouldn't have to chase employers for superannuation payments. ( ABC News: Michael Barnett )

"You look at your timesheets, you look at your payslips and the super contribution is there," bartender Jesse Lewis said.

After 12 years in the industry, he has less than $100 in his super account.

"It's up to the employer to pay that. Not for us to be having to chase it down from them," he said.