If the airline refuses or ignores your claim, then you need to enforce your rights by commencing a legal action within a specific amount of time of your flight. The limitation period is set out in the applicable provincial statutes.
If you miss this deadline you lose your right to compensation.
Where and How to Commence Legal Action
You may choose between numerous venues for suing the airline, including:
The province where you purchased the ticket.
The province where the final destination on the ticket is located.
The province where the airline has its principal place of business.