Unfairly listed

Hi my Name is Edward and I have been blacklisted unfairly by discovery health, I have never taken any product from them and yet they sent a letter of demand and listed a default under my, I have been calling discovery for over two months now to try and resolve this issue and I'm always promised that someone is going to call me back and no one ever does, there is no proof of any correspondence between my self and them which begs the question how do I owe them. I used to think that discovery as an organized and reputable business however my current situation has me thinking the opposite.