Landlord cheated me with respect to the property's leakage problem.

I am staying on sixth floor of seven story apartment. I got this flat through agent. Owner told me that there was some leakage of toilet which he got repaired. However even after leakage was not stopped. I called owner and he brought one builder to handle the problem, builder said that it will take 40 days to clear the leakage problem. Accordingly owner took builder to the flat owner of seventh floor. Where that owner refused either to allow repairs. Owner did not gave me any idea about leakage problem before handing over the flat thus he cheated me. until I deposited rent. What can i do now?