Mobile Device visible on account even after successful return

I disconnected Xfinity Line and returned the Xfinity Mobile device to Mt. Juliet TN Warehouse address given to me by the representative, even after getting a confirmation from Xfinity Mobile Billing Department that device is received at warehouse on 11-Dec, still the device shows on my account and my return is not closed. I tried following up with customer service multiple times but it didn't help at all. The CS were not able to generate the return shipping label due to technical issue and asked me to go for unsolicited return for which the carrier ( Fedex, UPS ) were clearly clueless, ultimately I paid shipping cost out of my pocket for which I was assured by agent to get re-imbursement on my credit card which never came in. This is really serious that, even after following all the directions from agent I am not getting right support. Please help me out if somebody can, hope to see a progress soon on this..!!