T-Mobile is the only ones that can unlock the phone. It is going to be a pain in the rear to deal with, but call them during business hours and escalate to higher tech tiers.
Try your local Best Buy or carrier stores, but at this point I'll just wait till the end of November for all the deals.
Sent from my Moto Z (2) using AC Forums mobile app
For removable batteries I went with the Z2 Force. The battery mods act like a extra battery and they are always on sale. I got an incipio battery for 10 back in November.