This "promotion" was a complete SHAM! T-Mobile lured us by stating: "trade-in an eligible device and purchase a new Apple Xr, Xs, or Xs Max to save up to $390..." (My particular phone was eligible for $250 trade credit. Uh, yeah, sign me up, please!)
But the key requirement to the offer is that the iPhone must come from your local Costco Warehouse's inventory! You couldn't just walk into Costco and order whatever iPhone XR you want, if they didn't have it! (T-Mobile completely fails to mention this on their website: Costco 2018 Q4 Apple iPhone XR Trade In Trade Up). And, here's the problem: Costco barely had any inventory, if any at all, on the iPhone XR before the promotion ended! I wanted a 128 GB XR, in ANY color, but I kept checking with my 2 local Costco Warehouses every other day--either via phone or in-person--for 3 weeks (the "promotion" ran from October 19th to November 8th), but they never got a single 128 GB phone in stock during that time! Consequently, I never got a phone.
Shame on T-Mobile and John Legere for running this bogus offer! What was the point? It did nothing other than make us T-Mobile customers angry!
(Yes, I know T-Mobile is running a similar promotion through their web site and in stores. But, the trade credit comes in the form of bill credits over 36 months rather than a lump-sum rebate--via Prepaid MasterCard--with the Costco promotion. So, if you want the full rebate, you've gotta stay locked into T-Mobile for 3 years! Yeah, no thanks! I remember when T-Mobile was the UnCarrier. Now, they're playing games just like the other 3.)