Mould

Just wondering if a tenant can threaten to not pay rent if some mould has come up. Basically what happened was my Pm informed me 5 days ago that the roof had a leak during heavy rain and the wall inside and carpet below had been damaged. The plumber went yesterday to inspect and said that he had to add an overflow downpipe to the gutter as too much water was going into that gutter so it would back up during heavy rain. He then showed me the mould and I made a claim first thing this morning. My PM has just told me he’s being hostile saying the house is unlivable even tho it’s a very mall section with about a foot of mould in the corner, and has threatened to not pay rent. I literally could not be doing anything more to rectify the issue