Call conférence not free?

Hello,
I organized an associative meeting on 05/25/2021 on https://meet.jit.si/
One of my members with an unlimited plan was billed € 51.84 by his communication operator on the number +33.1.87.21.0005 which is supposed to be free

Sorry for your experience. Those numbers are dial-in and there is no way for us to charge users for that. You need to clear the problem with the operator why you were charged for the call.