That is what I did recently.
Here is another specific example concerning Air Canada Cargo. I took something to Ottawa airport and noticed that the signs in the parking lot were in English only. In addition, the exit doors inside the airport were marked “exit”. Since that bothered me, I filed a complaint. The Commissioner of Official Languages said I was right, and Air Canada said I was right. I do not usually complain for no reason. I would even go so far as to say that my complaints have been founded in 99% of cases.