Greenboard or Waterboard around shower

I just had a contractor totally botch a bathroom remodel. He did not solder or insulate pipes around in the shower and we had to rip out the tiles over the shower body. It now appears that no greenboard or wonderboard was used. In addition, it seems as thoght he contractor just put tile on the drywall without taping or spackling the walls. We have ceramic tile. What is the proper way to do this?