i had half of my alprazolam prescription stolen out of my locker at work. the only two people besides me who could access my locker is my boss and his newly appointed lead and cousin. i left a message with HR but they did nothing. my prescription is a con

I was at work on Feb 29, 2016 and due to my mental health conditions i usually kept all my prescriptions in my bag in my locker with is locked by key card access or a security code or employee number that only the supervisor knows. However, the lead is the supervisor's cousin and asks me regularly for my medication with no avail. He asked me on the Thursday for a pill and i said " No I see my doctor today." Then on Friday he asked not for any sort of my medication. Then after I got off and went home i went straight to bed as my alibi/fiancee will testify. Then i woke up on Saturday, poured out my script and noticed that half were missing yet neither one of my other prescriptions were touched. I am sure it was my supervisor's cousin and do not know if he had anything to do with it. Although, my supervisor has been very negative and disrespectful to me ever since. I do not know where to turn and feel exploited and taken advantage of. We have several safety hazards and drug users at my employment but I am timid to take action. Please help!