Getting Bills for an Account that was closed 6 months ago!

I'm getting bills that seems to be attached to an account I closed months ago. The phone number isn't any number that I've ever had attached to my account. Have talked to someone on the phone and they said they would review it and I would hear back in 30 days. It's been way longer than that and I have heard nothing except to receive a new bill. Tried to report to fraud department but was on hold to talk to someone from 45 mins. with Kids and Work I don't really have that much time to wait just to report this to someone.