National RV Detroit bad service belleville Michigan

Purchased a camper in March 2016. Started having issues with air conditioner, molding falling off & radio/speaker issues 2 months ago. When we purchased the camper they told us they would come to us for repairs if we had any. Problems started in July, 2016. Had to threaten them with a lawyer if they didn't come out to fix the issues. They came but only fixed the molding. I have called & emailed them almost everyday since then. No response form anyone. Occassionally the guy who sold it to us will answer & say he is working on it but still nothing has been resolved. They sold my friend a camper the year prior. They have several repairs that need to be done as well. They have been waiting 14 months & still nothing has been fixed. Stay away from National RV in Belleville MI. I think I may have to get a lawyer involved. When the molding fell off it hit my daughter who was just laying on the couch watching tv. Any advice on how to handle this situation?