Kitty City Cube and Platforms (Textile Replacement), Red, 15.5*15.5*16 inch

What additional parts are needed for this item

My fur baby has scratched her post completely to pieces. Can I just get replacement scratching post?

Since this cube is spring supported on only one side is it not able to be used independently from the rest of these components?

Can i just get the textile replacement and not the city cube?