Paris, you don't even know how snooty you are

The other day, I had to drop a French literature class, so I went to the French UFR (i.e. ze Frrench department) to see if this was possible. “What? You want to drop a class?” They joked. “Mais pourquoi?”
“Il y a un conflit,” I responded. They laughed.
“A conflict of interest!” mocked the lady.
“Um, no, a scheduling conflict,” I replied.
“Conflict is English,” said the lady. “Here, we say chevauchement.” At this point I got angry. Why are the French so adamant about correcting everyone all the time? Admittedly, the conflict might have been caused by an overlap, but it remained a conflict. Must I change every single thing I would normally say just because the French like it better that way?
“Listen,” I said. “I come from a place where when we speak French we don’t use words like email and weekend, so don’t you tell me that my French sounds English. There are other countries in the world that speak French besides France, and not everyone talks like you!”
The skinny lady and the leprechaun-like man were stunned. Yes French UFR faculty, it is bad form to criticise the francophone exchange students about the words they use you might not otherwise employ.