Where is this Fictional Back Office?

I am also wondering about this Fictional Back Office. I've spent HOURS over the past 3 ½ weeks just trying to get an answer on where my replacement phone is. After the rep is "searching the computer" for my "case" (each time I contact AT&T I'm given another case number) and after an hour on the phone explaining the situation for the umpteenth time, I am either transferred to ANOTHER person where I have to start over, or told "it's in the back office there's nothing we can do", and each representative tries to sell me other features. All I want is my replacement phone that was NOT delivered to my house by FEDEX on Dec 20, 2018 .. which was reported to AT&T THAT DAY.. and each time I contact AT&T I'm either told "Oh you should get it in 3-4 days (been told that twice and it's been 3 weeks)" or "It's in the BACK OFFICE and there is nothing we can do". Seriously? THEN the phone I haven't received appears on my bill. Been with AT&T for 17+ years. Very VERY disappointed and a little disgusted.