Canada's telecom regulator says four air duct cleaning companies paid a total of $55,000 as part of a settlement following violations for unsolicited phone calls to potential customers.

After consumers complained about violations to Canada's Unsolicited Telecommunications Rules — the so-called "Do Not Call" list that bans unsolicited business offers via phone — the Canadian Radio-television and Telecommunications Commission launched an investigation into nine Toronto-area duct cleaning companies.

In addition to the $55,000 paid by four companies, the regulator also says it issued notices of violation accompanied by monetary penalties totalling $94,000 for five more.

"We are pleased to report that four of the nine companies cooperated with the investigations and have voluntarily ceased making unsolicited telemarketing calls to Canadians," the CRTC's chief compliance and enforcement officer Manon Bombardier said in a statement.

The list of companies that have paid, and how much, is as follows:

Bridge Home Services Inc. – $6,000

Cambridge Heating Services – $23,000

HR Home Services – $3,000

Top Line Air Duct Cleaning Inc. – $23,000

These five companies were issued a notice of violation and an administrative monetary penalty, and now have 30 days to respond:

Aqua Duct Cleaning Services – $9,000

Goodlife Home Services Inc. – $16,000

Kareem Duct Cleaning – $15,000

N. Bro Transport Inc. – $14,000

Toronto Breeze Air Duct Cleaning Services Inc. – $40,000​

All nine companies used foreign call centres to make the unauthorized calls, and the CRTC says it sent warning letters to seven call centres located in Pakistan, India and the U.S.

"The CRTC reminds telemarketers that it is their responsibility to adhere to the rules, whether they make the calls themselves or through a third party in Canada or abroad," the regulator said in a release.

Since being implemented in 2008, more than 12.8 million Canadians have signed up to be on the Do Not Call list. The CRTC says Canadians can register their numbers, verify whether a number is on the List or file a complaint about a telemarketer by calling 1-866-580-DNCL (3625) or visiting www.lnnte-dncl.gc.ca.

So far, the CRTC has issued monetary penalties worth over $6 million and other penalties worth $741,000 for violations to the list.