Paradise Grilling Systems Product falling apart Orlando Florida

So. We purchased an outdoor Kitchen from Paradise Grilling Systems at the RI Home Show 2016. We sealed it per paper instructions and covered in the winter. What we found when we uncovered in March 2018 was the slate had disintegrated . We paid $7847. A lot. In March The company reluctantly agreed to have repaired and workers would arrive late May 2018. I would need to pay $150 for repair and they would give us free slate. They then agreed to no fees charged. The box of 12 slate pieces arrived weeks ago. Today they tell us NOWAY. They will not return my calls. They claim we have extreme weather in the North, although they were selling at our northern Home show in my State. I have notified the RI Home Show administrators and am sharing online. No where in any paperwork does it state "Do not use in Northern States”. They also claim they approved repair before viewing pictures. NOT TRUE. I have emails to prove they viewed pics then approved. I also have emails stating they will repair.