When I called T-Mobile, I was shuffled to five departments, everyone of which had heard of the 200 MB plan, but none of knew how to handle it. The store had predicted this saying I needed to call 1-800-937-8997 and be very explicit. But it did not work.
Based on tips on this forum, I browsed to https://mim.t-mobile.com/ on an iPad A1337, and got this nice page:
Welcome to mobile internet management. Your new mobile internet device comes with up to 200 MB free data ever 30 days for Lifetime. To get started with service activation, please choose one of the options below:
Below there was just one option: "[Current T-Mobile Customer]", which when clicked results in:
We're sorry! The Mobile Broadband My T-Mobile site is down.
It gives a phone number, 1-877-453-1304, but the person who answered had no clue what to do.
I have a T-Mobile prepaid account.
How can I register this device? Why is the web page listed above not working?