Rude Agent drops line in my ear.

I recieved a call from your collections department and spoke to a gentleman , I am unfami**** with his name as he refused to give me when I asked. I am traumatised by the attitude and rudeness I recieved from this agent and when I asked him for reference he proceeded to refuse and dropped the line while I was speaking to him. The call is concluded without me knowing where to from here with what he called me for, iv never been disrespected in this manner before in the name of incredible connections.