Phal with black hole

[erkell]

Hi there,

I have a Phal that I received as a gift 4 months ago. I never re-potted it (probably a mistake) as it seemed to be going well (2 new leaves and new root growth). Recently I have noticed a dry black hole at the leaf base (almost looks like a cigarette burn). On the other side of the plant there is a black lump that I have never seen before! In the past week the roots have also started looking poorly. I am in Australia (middle of summer approx 35-40C every day) so I have been keeping it in my bathroom in a window with indirect sun and watering 1x/week, and it's in sphagnum moss and plastic pot w. large draining hole.

I am desperate to save this as it was a gift in remembrance of my Retriever who passed away recently.

Any help at all would be wonderful.
Thanks!