unfare exclusions

I have adopted a dog from the SPCA . She is 2 years old. I know ther is a 30 day waiting period and of course my first claim was not paid. This week I submitted a claim for pruritis for my dog and it was not paid (although the waiting period is up) as they say she had the same thing during the waiting period. I ask you what can of logic is that ? She could go on having it as a chronic disease.That means they will never pay for it..I find this illogical and ********. Unfortunately most pet insurances do that. I spent 1800 at the vet. Nothing returned. What do I pay insurance for....