Xfinity Support for trade in phone

My trade-in phone has been lost? I dropped it off on Monday, 10/6, and there has been no update on the shipping label. This is obviously a recurring issue with Xfinity, as many other people have posted the same complaint. Had I known this, I would have NEVER accepted the mobile line offer and new phone with trade-in. I have already submitted a missing package ticket with USPS. I am asking Xfinity support to please advise on what to do next. I am terrified that the phone won't be received before the due date of 10/20 to receive the trade-in offer. I spent over $480 dollars to pay off my old phone, and I am going to be very upset if the trade-in offer is not honored.