no assistance

I phoned outsurance on Friday the 14th of October for structure damag to my outside wall that is bussy falling over. The assessor came to do the assesment and told me that this is a structure problem and that the insurance needs to pay for this. Inside the house the walls ar also cracking and the tiles where all seams are the assessor told me that this is the foundations that is setteling but how is it possible that it is only after 20 years? Now outsurans is revusing to pay for my outside wall that is bussy falling and it's going to leave my house open for any one to come in