Unfortunately, an "as is" purchase means exactly what it sounds like you agreed to buy the home in the condition it was in, whatever that condition was, and give up any claims for defects or problems. You could bring the contract to an attorney to review--contracts, including home purchase contracts, are enforced according their plain language, so it's possible there was some exception or loophole you can take advantage of but barring that, you most likely do not have recourse against the sellers.