My manager, who I reported to HR a few short months ago, just got promoted

I work at a large corporation and my manager is a slimeball who berates me behind closed doors and then acts sickeningly sweet when other people are around. I had reported his behaviour to HR and they said they would deal with it, but he has not only continued this pattern of behavior, I found out today he got a huge promotion to associate. I'm disappointed with my company, I really thought they had my back and now I just want to leave. Now this guy has even more power to make my life hell.