Cancelled business service. Balance at $0. Still $130 dollar "one time charge" on the bill.

Not sure what to do with this now.  I'm assuming the $130 was for a box still lingering on the account.  Everything was turned in a year ago, and someone from Comcast followed up with me about the box which I told them is no longer in my possesion (and doubted I had a receipt from since it was a year ago).  The lady on the phone said this would go away.  Sick of getting paper bills (glad I signed up for paperless) that are telling me I still owe $130 on a business that moved a year ago, and the building was sold last month.

Can someone get in touch with me and make this thing go away?

Tulio