Now I can read the meaning. That 한방 means the Korean traditional medicine. "한방머리 했어요" means "I had a hair treatment in the Korean traditional medicine way." This means they applied the person the 한방 style which contains ingredients used in 한방. I think this is right because there are many products using Hanbang ingredients. Hope it helps. :)

I read it here: 한방머리 했어요 >_<

It seems quite subtle. More context or sentence is needed. There is a slang "한 방" or just "한방" that means "one shot/hit," but it's not clear whether that is it.