What do I do if a boss is a good friend of a coworker who has sexually harassed me?

I work for a large retail chain and I was put into a position in the backroom to take care of overstocked merchandise. One of the coworkers, who has worked there for three years and is friends with one of the managers, took me into the small receiving room to show me how to bin the merchandise. While there (the area was very small) he started to tell me of a tattoo he has on his private area. When I tried to talk to a manager in private I was told that this coworker is a great worker and that we would just have to get alone. Mind you, I did NOT tell him the exact conversation out of embarrassment. It has been about five months and even though the coworker hasn't said anything else about that conversation, he does make grunts and moaning noises when I am on a ladder, but doesn't do it around other coworkers. When I tried to ignore this coworker or let him know I do not like him, I was taken out of the area and placed in very difficult areas of the store by the manager who is his friend. What can I do to stay in the area that I am very good at and keep my distance from the coworker and the manager? Also, I just filed a report about the incident and I was told at least twice in the meeting that "if I am believed" something would be done. It is my word against his and according to my other bosses no one has ever complained about this particular employee but me. I know that is a lie because everyone talks about how this coworker is. Can I lose my job over this? Can the company move me instead of him because he has been there longer?