Exchanging Canadian drivers license (Paris)

Hello lovely Paris-dwellers! I'm hoping someone can help me out here. I went to the Paris prefecture last week to sort out getting myself a French drivers license, as my 1 year anniversary of driving here on my Canadian license comes up in September, after which I'll need a French license to keep driving.

According to this government site: Protected content (as well as every other government site with instructions about this), being that I'm someone with an international/non-EU license and live in Paris, I need to show up to the Prefecture de Police de Paris in person with the documents listed. Easy, cool.

I show up at the prefecture, and they tell me, "no no no, you need to send these documents to us by post and not bring them to us in person, after which we'll schedule an appointment for you to come to the prefecture to show us your original documents" (?!?!?). They also gave me a brand new printed handout with a whole other list of documents I need to bring: a letter from the last three months from the Ontario government saying I still have the right to drive (officially translated), an official translation of my drivers license, despite it being translated into French on the license itself already etc., as well as some other complete departures from the instructions I've found everywhere else online (apparently the photos can't be stuck to the photo boxes on the forms already so I have to go take new ones again).

So, WTF. Has anyone else gone through this process and can lend me some advice? I don't think I will have time to get a confirmation of my right to drive document back from Canada (apparently processing times for getting this document in Canada are Protected content alone), officially translated, and submitted on time.

Are there any prefectures that will honour the instructions written on the government site I listed above?