Hi, my trade in packaging came a few days before my phone, keep calling customer service & make sure to get a reference number to use as proof of contact, keep sending emails to customer service to proof you're trying to resolve the issue, keep calling until they accept it's them at fault.
Worked for me.
I sent in my device with their return packaging via recorded delivery, it arrived the day after & was signed for, but I kept getting texts & emails saying they still haven't received my trade in device for return, so I kept sending in my proof of receipt about three times until they admitted fault & said that they had received my device.