That aphid infested plant has to be sacrifice to ensure situation contained. I decide to re-pot and trimmed all leaves from this plant.
The black aphid reappear, but the ants are no more around.
I had to cut all the leaves and get rid all this aphid, need to visit the local flower nursery to find more potent organic spray to ensure they don't reoccur.
They are even in the crown area.
Trimmed and re-pot and will monitor closely.
Hope this plant survived the ordeal.