Trade-in device shipped with USPS is not moving and I'm worried about losing trade-in credit

Hello, I shipped my trade-in device (iPhone 16) with the USPS shipping label provided but looking at the tracking number I see that it has not moved since Friday 10/09. I tried to drop it off at a Xfinity store as your website says and customer support on the phone told me I could do but the store said that wasn't true and I could only ship it. Now I'm worried about the package being stuck/lost in transit and not getting the full $724 credit for my trade-in device that's in excellent condition applied to my account even though I sent it within the correct timeframe. I have pictures of the device I took while packaging with the USPS label provided by xfinity. As well of proof of drop-off at the post office with the tracking number. Can you please help me with this issue?