If everything is in French, I suspect they would assume that your degree was in French especially if it's a Canadian university. Can you request a letter from your university clarifying that the program was in French?
I uploaded a copy of my US diploma (it didn't say anywhere that the program was in English but everything on the diploma was written in English) and had no issues with the language requirement.
I have 2 bachelors, 1 from France and 1 from Canada (Montreal University), Both bachelor certificates are in French with the university name, of course they won't provide degree program in Italian..
Also I found a transcript of my 2nd year here in Montreal University, everything in French including the courses names (+ luckily, one of the courses is the English one).
I will upload the 3 documents.
I had TEF exam back in 2015 I got C2 In the needed modules (Oral expression/comprehension) but I cannot find the certificate at all, I guess I sent it with one of the documents in the past years. If they dig into the records they should find it..