My human resources person did not conduct an investigation for a sexual harrasment claim what should I do

I'm being sexually harassed at work by upper management I reported it to my supervisor who reported it to human resources and they did not conduct an investigation. And the guy keeps touching my butt and asking me inappropriate questions about my body. My supervisor told the harassor he was offending me but that didn't stop it. HR told my supervisor that I had to come tell her in person but that's not what it states in the employee handbook. Someone witnessed the harassment prior and reported it and an investigation was not done then either the harassor just stated he got wrote up for it. If he hadn't said that I wouldn't of even known about it. He has done it in front of my colleagues who then decided they would throw in their sexual comments since they thought I wasn't doing anything about the other guy doing it. What should I do?