All right, I understand. Thank you for your question.
I would suggest filing a complaint with the Office of the Commissioner of Official Languages. You do not need to be the person who is denied service. If you observe a breach of the Official Languages Act, you may file a complaint. What happens—and you can check the minutes of your previous proceedings, or you may already have done so—Air Canada still says that no complaints are being filed. I think the best thing to do in that case is to file a complaint. In any given situation, if the Office of the Commissioner of Official Languages receives 5, 10, 15 or 20 complaints on the same subject, that may eventually help the cause.
I really think that would be the best way to do it. It is also possible to go and find the person responsible, if he or she is a unilingual anglophone, and to ask whether that person knows he or she is required to provide service in French. That can be done. What I have learned over the years is that it is not always the fault of the person behind the counter.