Terribly Disappointed

The roof of my granny cottage collapsed after a week of having had a new roof structure being put over the old one (which had borer damage). After 2 weeks I was informed that my claim had been rejected due to borer damage. How could 8 new and treated rafters get infected and collapse within a week?? I had also submitted proof of purchase for the material of the new roof. My contractor informed me that a weight bearing wall on which the old and new rafters were placed on had given way thereby bringing down the entire roof including the old, obsolete and damaged rafters. The engineer who examined the rafters only looked at the borer infected timber and based his decision on that. He never once looked at nor questioned about the 8 new rafters which were not infected by wood borer. So, was it the “damaged” rafters that had given way or was it the wall on which the rafters were placed on?? I had been I loyal client of Outsurance for many years, but now I feel terribly disappointed as I feel that I have submitted a valid claim and I am being made to feel that it’s my fault for not having maintained the roof structure. I had gone out of my way to recommend family and friends to Outsurance. Now, I am really going to look silly when I inform them about my latest experience.