It should be as in the G4Polyhedra constructor:
https://geant4-userdoc.web.cern.ch/UsersGuides/ForApplicationDeveloper/html/Detector/Geometry/geomSolids.html#constructed-solid-geometry-csg-solids
G4Polyhedra(const G4String& pName,
G4double phiStart,
G4double phiTotal,
G4int numSide,
G4int numZPlanes,
const G4double zPlane[],
const G4double rInner[],
const G4double rOuter[] )
zplane come at the end instead.