Comcast loses my HD DVR box - now I have to pay or they put it on my credit report!?

I am dealing with "supposed" unreturned equipment from Comcast. Just received my bill for a $380 cable HD receiver that I supposedly never returned. I cancelled my TV service with Comcast in early Jan. of this year after dealing with horrible customer and television service. I did not discontinue my internet service at that time. I returned the cable box to the service center on Babgy St. in Midtown (which is now apparently closed permanently) in January.

I finally cancelled my internet service on June 1 - and now all of a sudden I get a bill for the cable box 2 weeks later. I returned the thing when I cancelled my TV services. I had a receipt but after moving 6 months later - I can't find it. Didn't realize 6 months after cancelling my TV service I would need proof I returned the receiver.

I've made multiple calls to Comcast requesting the charge to be taken off. Supposedly the warehouse "looked for it", but no one is quite sure whether they did or not. No one you call knows what the next step is. I have left voicemails with supposed "supervisors". No one returns calls. (I even asked to be called back about my customer service experience and that doesn't happen) And if this charge is turned over to a collection agency, I will be forced to escalate this issue. It's not fair to me that Comcast has made a mistake with THEIR inventory! COMPLETE INEPTITUDE!!!!!!!!

Somehow not surprising with the poor customer service I received while a customer. And there's nothing I can do since I don't have the box - I already returned the thing! This just shows a lack of management and inventory policies at Comcast.

I will be sure to post this problem on every website I can and inform everyone I know of the HORRIBLE treatment from Comcast and how HAPPY I am with my NEW service providers!