Telescopic Clothes Line Prop Heavy Duty Extending Washing Cloth Line Prop (1 Prop)

After spending 20 mins opening this, I have no idea how to put it together? I think there are bits missing.. no plastic screw as mentioned by revie.

is the post made of plastic or metal

After trying to un wrap this it does not work or extend and is bent too very upset

Could anyone tell me the diameter of the widest section of the prop?