RETURN DEVICE PACKAGE EMPTY

HI Im really stressed out right now i warranty my phone sent back my phone with your tracking number 1Z9E86E78736404657 t mobile rep said you folks got the box but device wasnt in there and trying to charge me 1300 and now my phone is off because of that please HELPPPP im looking into getting a lawyer to help me out i have cameras footage of me going into store and giving them my phone and i paid them $9 to bubble pack it and send it to you folks as well please help