Think twice before taking out BetterSure Building insurance.

I have just bought my dream home and was as required by the bank took out building insurance with Bettersure. We moved into the house in September and in November had two really bad storms and the roof leaked into the ceiling and into the light fittings in the kitchen. I called Bettersure and arranged for someone to come out and have a look. the told me the process would take 10 working days. 15 days later I had to phone them only to be told that they have rejected the claim. No one is able to tell me why? A leaking roof is apparently not covered? I shudder to think if it was something more serious if that would be covered? I will be moving my business right now but because I have paid for this month already I don't have a choice.