Still can't remove mold from walls - what am i doing wrong?

Bleach is probably the problem. On painted plaster it whitens the surface so it looks gone, but the mould is still rooted underneath and it's back in a month. Use a proper mould remover or fungicidal wash, let the wall dry completely, then repaint with an anti-mould paint rather than ordinary emulsion. And if it keeps coming back in the same corner, it's condensation, not a cleaning problem - open the window after showers and cooking, keep wardrobes a few inches off cold outside walls, and get a dehumidifier if the windows are running with water every morning.