DAR Waterfront & Associates They have sent me a notice of a past due account on an item I have never heard of nor purchased. Sherman Oaks California

Reference #:  10063766

I received a past due notice for an item I never purchased.  The letter said that I must respond in writing if I am disputing this debt.  When I called the telephone number it stated that I could send them an email at www.darwaterfront.com/dispute but when I tried to send them my response it is not an acceptable address. 

I will follow up with a written letter but I do not trust them.  I would appreciate anything that you can do for me.  I do not want my credit ruined because of this issue.

Thank you for your help.  Anything you can do will be appreciated.