UCB, Florida United Collection Bureau UCB will not stop calling for my ex husband of over 10 years. They keep harassing me and won't stop calling Fort lauderdale, Florida

I have been receiving harassing phone calls from UCB for over a year now. I get collection phone calls from them for my ex-husband of over 10 years.   Everytime I speak to a customer service representative, I get told that they have taken my number off of his account and that it will not happen again.  The very next day, someone else calls and again harasses me.  They want my ex's phone number and address and honestly, I would like it too so I could pass them on to him.  My ex hardly ever contacts our son, so I have no idea where he is.  The last time we were in the same room, his pyscho girlfriend attacked me because I brought him to court for back support.  So, I try to stay away from these two people. 

I just want the calls to stop, they call several times a day, more than one day a week and they laugh at me when I say I don't know where he is.  Guess I won't hire them to collect the $30K I have coming to me in back support, as they are doing a really crappy job in finding him.