Aren't this cars officialy called Megane Scenic instead of just Scenic?

From 97-99 yes.

As of the first generation facelift model just Scenic.

OK. But on every Scenic they have booth Megane & Scenic badge. Scenic badge on rear of car (trunk). Megane badge is between 2nd(rear door window) & 3rd window.

Mark0 wrote
i dont think. Officially, only the first not lifted is called Mégane Scénic

Yes, it was only the first 2 years of the original that were called Mégane Scénic. When Renault facelifted the Mégane Scénic in 1999 (Série 1, Phase 2), the official name became Scénic, though a Mégane badge did remain on the rear, probably to identify the vehicle's origin, for at least the '99 model. Feel free to correct anything I got wrong.