Ipso facto; by expressing your frustration you put yourself on the back foot in this situation.
If you had kept your composure, checked in THEN asked for a manager I'm sure that manager would have taken your complaint seriously immediately.
My conclusion; you are at least in part to blame. You say you'll avoid France in future. I doubt France will lose sleep.
I've flown through France many times and I've never had a rough time.
Approached in the right way all the staff at CDG have always been pleasant if at times efficient.