Note that the Employment Standards Bureau in BC clearly states that TFWs have the same protections: http://www.labour.gov.bc.ca/esb/facshts/foreign_workers.htm
That the office in Dawson's Creek said they couldn't help because those workers were TFWs is disgraceful and should be investigated because if true it represents a fundamental failure of the system to properly protect workers.
One very important part of this information:
Another excellent publication: http://www.cic.gc.ca/english/pdf/pub/tfw-rights-english.pdf
The Tim Horton's employees in that complaint are clearly subject to exactly this type of treatment.
If CIC finds that someone has been subject to Human Trafficking, the law allows them to issue a Temporary Resident Permit:
This can lead to an open work permit and eventually eligibility for permanent residency - though this requires the TRP permit holder remain in Canada under a valid TRP for five years. At that point they are eligible in the Permit Holder's class.