Claims declined due to policy schedule not having all information. Service is pathetic seeing that OUTsurance is such a big company

I had an issue where I went out with my family on Saturday around 4pm and returned home about 9:30/10pm and found my home flooded with my toilet overflowing, Pipe linked to main pipe that goes into the cistern and the washer broke, allowing the water to overflow. accessor came and investigated this damaged where floors and cupboards were damaged due to the flooding and declined the claim due to not being covered. I questioned this and was advised by a team leader that it is stipulated on my policy schedule that it’s not covered, upon requesting the policy schedule and reading this long document there are no wording to the exact or similar to state that OUTsurance does not cover this and was advised by another advisor there are too many stuff to mention hence they do not put all on the policy schedule. OUTsurance please advise and give clear explanation as what was advised is contradicting.