If you have a good relationship with an HR person, and trust them enough to ask for informal advice, some positive action can follow. If you want to go the formal route, if you use words and phrases that sound like a lawsuit in the making, expect an action to your disadvantage. HR is there to protect the company, not you. An obviously disgruntled employee crying foul is immediately perceived as a threat to the company, regardless of whether they're objectively right or not.