Unfortunately, I've been down this road too and it proved to be the biggest time-waster and source of frustration imaginable.
Remember last year's T-Mo promo where you traded in a phone and got a credit each month? Well they listed the right IMEI number, but the model number was incorrect. I was assured in a 30-min follow-up phone call that only the IMEI number mattered and all would be ok. Glad I took pictures of my device before sending it in, because Assurant solutions rejected it. It then took me 5 months, hours of phone calls, and numerous emails to get that one resolved and get the monthly promo credits that were promised.
This may sound like an exaggeration, but between last year's launch and this year's launch, I know I have had to invest at least 20-25 hours of my time just to get things squared away. And I'm not abnormal...I don't call for no reason to check on my order status or any of that crap. I simply place an order for phones, I make sure they call back the info to me to ensure they input it correctly, and then somehow T-Mobile just screws it all up.
The next thing I'm doing is getting an app that lets me record phone calls and I'm going to record every single call I ever have with any CSR from any company from this day forward. I'm sick and tired of them telling me one thing only to discover something else later. Happens all the time and not just with T-Mobile.
Hey, I really do appreciate your feedback on the IMEI number (don't want to sound ungrateful). It's just that I was royally screwed over this last year and I'm not going through that butt pain again.