Written notification about debt: Debt collection

I SEEN ON MY MOST RECENT CREDIT REPORTS THAT YOU ALL ARE REPORTING AN ACCOUNT TO MY CREDIT REPORTS. I DON'T KNOW WHAT THIS ACCOUNT IS OR WHY ITS BEING REPORTED BUT I KNOW ITS HURTING ME AND I NEED THIS TAKEN CARE OF ACCORDINGLY. I NEVER RECEIVED ANY DOCUMENTATION IN THE MAIL ABOUT THIS ACCOUNT. THANK YOU