Damp 2011 Coachman wanderer 19/6

Hi all. 

We have owned our van from new. First service detected 60% damp near side top rear corner and in bathroom area around window / flush fill. After much hastle and travelling to / from Hull the damp was apparently cured. 

At the same time as the above was going on the outer door blind went mouldy, all the internal doors, cupboards and drawers delaminated, the alarm packed up and the heater fan expired. Not good I'm sure you'll agree.

second service (this week) even worse damp found - 70% all around front - totally gutted. The van will be worthless when we come to change it based on its history - what's our legal position? We surely have a very strong fit for purpose claim? (Or lack of)

thanks

mark