Thank you so much for responding! I've searched Google and apparently there's been many more cases like this.
I have already contacted USPS but they said they'll "look into it". What I don't understand is how two packages dropped off at the same location, at the same time, going to the same place, ends with one being delivered and one basically going missing. It's been a week and the status still hasn't changed from "Acceptance". I have a receipt with both packages listed as being received on it so I hope that counterclaims anything they might say about me not even sending it in.
I have also contacted T-Force and explained the situation to them but they seem like they don't understand why I'm getting so worried. They say "it sometimes takes 7business days for the item to arrive to us" blah blah blah. I really don't know what to do now. I have no hope that USPS will find the package and I'm not sure what T-Mobile will do. I did everything I was supposed to and it would really suck if I lose my phone while also having to pay for the 7.