Mold...Lease-what rights do I have as a tenant?

3 wks ago I called my landlord about black mold growing on my bathroom ceiling above my toilet. I suggested it may be from tenant above me, perhaps a leak from his toilet or plumbing, considering location (mold was growing under where his toilet sits.) My landlord came, swiped it w/ bleach, said that it wasnt from a leak and basically insinuated that it was my fault for not keeping the bathroom properly ventilated. I contemplated breaking my lease, but decided to wait it out. The mold is starting to slowly grow back in spots, the drywall itself is dry rotted. Today I noticed when walking out the door, that the carpet in my entryway was sopping wet! I called slumlord again, upon his inspection, he said that the above tenant's hot water heater had burst, (as I suspected) resulting in leaking water running down my walls, drenching my carpet. He said to just run the air conditioning (its 30degrees out) and it "should work itself out."