Outsurance wont pay for termite infected hollow wooden floors that was covered by carpets

Family member bought their 1st home and the usual test were done and on the 1 inspection because the home had carpets fitted it was mentioned that could not test the wooden floors. They now lifted the one carpet in the passage only to see that it was termite infected. And once walked over it a whole appeared as the wood is weak. They called their insurance company outsurance and was told that they wont pay. What is their rights. As young 1st home buyers they according to me have been done in. 3 quarters of their home is hollow wooden floors which might be I'd carpet is lifted could also be termite affected.