If you have a problem at work there are number of different ways, formal or informal, that you could try to help sort thing out. Before taking action you should try to work out what the problem is and make sure it isn't a simple mistake or misunderstanding.
Nearly every organization has its share of difficult people. In many cases, you can ignore them, but ignoring is impossible when they are your co-worker or managers. Unless you can't change a difficult colleague's personality, you can control your own reaction to that person ( by keeping your temper, refusing to act like a victim and building alliances )