Need a Roofers Pro Opinion?

I have a palm harbor double wide and it has had a faulty roof since the day we got it. We have had the manufacturer crew here to repair so many times its not even funny to talk about anymore. Here in lies the problem...Every time the leaks in the roof gets bad enough for us to notice it on the inside such as seeing rain water run down the walls or puddles of water in spots in the carpet, or the sagging ceilings, or the weak-given walls, or the ground fault trips on the entire house every time it rains because there is water in the walls that affect the electrical sockets inside the walls. Here's the question..If I have that much water coming in the roof and running down the walls on the inside, and this has been going on now for 6 years...wouldn't you think that the wood in the attic space is rotting if nothing has been replaced the whole time this problem has been going on? Today the repair guys came because an entire 14ft ceiling panel fell to the floor, and they pulled out chunks of wringing, sopping wet insulation. Repair crew says everything between outside roof and inside ceiling is perfectly fine! It takes a while to notice it from the inside, so all that time its wet in between. Rott or not? Do you think I need an entire new roof or keep putting a big band aid on it?!