Cox cable communication they are charging me with someone else bill San Diego California

I had cox cable service for a year I moved away and i stopped service and paid the balance. I had my mail foward tomy new address, I never recieved any notice of any money owed. Like I said when I closed the account I paid the balance. I started work with a new company and they gave me a company cell phone the number was from an emplyee that had resigned.

Well cox called my new number and i told them this was my number now I had told them that i used to have service from them a few months ago. Well they attached the money that guy owed and said that it was from my account. I put in a complaint and waiting for thier response.  Cox is trying to stick me with that guys bill.  I feel they have a crooked system and lazy billing personall. Mike El Cajon California