Melbourne pensioner Doreen Ditchfield says that at 85, she should have known better.

But a charming travelling con man with a Scottish accent tricked her into handing over $7300 in cash to remove mould and fix the guttering on her roof.

The work was never done, and Ms Ditchfield is not alone, says Consumer Affairs Victoria.  In December, unsuspecting Victorians were fleeced about $300,000 in similar scams.

“I’ll change my name to Doreen Dill,” Ms Ditchfield told reporters.

“I was embarrassed that I didn’t wake up.

“I thought he was genuine, but I should have known because he wouldn’t take a bank cheque.”

A campaign to stop the travelling con men has been launched by Minister for Consumer Affairs Jane Garrett, supported by Consumer Affairs and CrimeStoppers.

The campaign includes advertisements in print and social media, and on TV and radio.

It urges Victorians to be sceptical of people who knock on their door and offer fix-up jobs – such as repainting the roof, cleaning the guttering or re-surfacing the driveway – for cash.

The con man disappears once the money is handed over.

Ms Garrett said perhaps the worst thing was that they targeted the vulnerable including “people like Doreen, those from non-English speaking backgrounds and increasingly stay-at-home mums and the disabled”.

In a seperate incident, travelling con men are tricking Perth seniors into allowing them to do shoddy roof repairs for a fee, prompting a warning from Consumer Protection.  Police have received reports of four men approaching elderly residents in Subiaco, Nedlands and Dianella, telling them their roofs need repair and offering to do the work for a fee.

The men, travelling in a ute, gave the residents a business card naming a legitimate roofing company, but the business told one consumer they were not employees.  When confronted, the con men on the roof quickly left the house, Consumer Protection said.

One of the men is described as 20 to 30 years old with an Irish accent, about 168cm tall, medium build, fair skin and short brown hair.

Consumer Protection commissioner Anne Driscoll said homeowners should not deal with door-to-door traders.

“These itinerant traders use high pressure sales pitches to get consumers to agree to have their roofs repaired at supposedly low cost,” Ms Driscoll said.

“The cost of the job is often more than it’s worth and the work is usually sub-standard.

“It’s also difficult to track down these traders for a refund or to make a warranty claim if the consumer is not satisfied.”

The con men also broke consumer law by not observing a 10-day cooling off period for unsolicited sales, Ms Driscoll said.