Almost four out of 10 people in Saskatchewan and Manitoba say they experienced a surge in unwanted calls from telemarketers, despite adding their phone numbers to a Do Not Call registry, according to a new survey.

"It's a disturbing finding," Brendan Wycks, the executive director of the Marketing Research and Intelligence Association, which commissioned the survey, told CBC News Wednesday.

While the number of people getting more unwanted calls was small, Wycks said it was significant and most pronounced in Saskatchewan and Manitoba.

"There are strong regional differences," Wycks noted. "It's 39 per cent who say that they are actually receiving more telemarketing calls now than before they put their number on the list."

Database started in 2008

A national Do Not Call list has been in operation since 2008.

'They don't pay any attention to international law.'—Brendan Wycks

Under the system, people can submit their land-line or wireless telephone number to a database.

Telemarketers are required to consult the list regularly and, using it, remove or scrub numbers from their systems.

Wycks said some telemarketers skirt Canadian regulations, a situation his industry noticed about three years ago.

"A lot of rogue telemarketing companies, in the U.S. in particular, started targeting Canadians in certain regions of our country which they believed to be more prosperous," he said. The companies believe their marketing efforts would yield results in those areas.

"They don't pay any attention to international law and international regulation," Wycks said, adding that authorities have tried to shut them down.

He said Canada's regulator has had some success in dealing with non-compliant companies.

But Wycks said it is a difficult field to oversee, adding that many people continue to receive unwanted calls from a machine that begins with a loud boat horn.

"It says, 'This is your captain speaking,'" he said. "If you stay on the line with it, at all, it ends up connecting to a live voice that tries to sell you a time-share in Florida."

He said people who are persistently bothered may try to record the unwanted calls and gather information, such as a company name, and forward what they can to the CRTC, as a formal complaint.

Complaints can be made using an online form, at www.dncl.gc.ca or using a toll-free number, 1-866-580-3625.

"That will form part of the CRTC complaint database," he explained, "and can help them to coordinate with their counterpart bodies in other countries."

Despite the regional problem, the survey provided encouraging news, Canada-wide, on the utility of the Do Not Call list.

On a national basis, 78 per cent of people surveyed said they were receiving fewer telemarketing calls after registering.

"For the vast majority of Canadians, it is working for them," Wycks said.

There are some exceptions to the list, including registered charities and political parties. However, most of them maintain their own Do Not Call lists.

According to a 2011 report on the National Do Not Call registry, nearly 9.5 million numbers had been listed as of March 31 of that year.

The report also said that there were 8,478 duly registered telemarketers participating in the system. The vast majority, 8,098, were operating out of Canada.