Proper ventilation is the key to get rid of the mold in the washroom. Keep the door open after using your bathroom. Then try half bleach half water solution on the mold. It really helps. Go for "Kilz" paint. It is specially developed for killing molds.
How Do I Kill The Mold On The Walls In My Bathroom So I Can Repaint With Out Problems And What Paint Is Best Against Mold?
Use kilz on the walls before painting with fresh paint and use a latex paint. Invest in a dehumidifier if the mold persist.