Lost baggage for brother

My brother just flew on April 18,2013 to arrive in Odessa Ukraine but his baggage never arrived. I called Turkish Airlines and they are  joke. They don't even listen to what you have to say and when you raise your voice and are firm they get even worse. The person that helped me didn't even ask me for a tacking number or even his name and stated he would call me back. When I stopped him and told him ,"I haven't even given you the name or tracking never, he got mad and stated, "I don't know where your bag is".I ended up hanging up on them because obviously I was wasting my breathe with them.. I will be suing them because my brother is very depressed and stressed. It's his first time flying alone and out of the Country and I will get  a medical report.. For loss and damages to his health