That's certainly a long time to keep hearing unfulfilled promises, I wish the situation had unfolded differently.
We don't have a way to collect info on tickets and check the status here on Support, which is what this situation would warrant. My suggestion would be to reach out to T-Force on FB or Twitter, you can link them to this to avoid repeating and they'll be able to see any updates if there are any.
You can find them linked in my signature!
Apologies again I'm not able to offer more direct assistance, but this is definitely something we want to check on ticket status for.
There are certain urban markets where T-Mobile has outgrown their spectrum holdings. Downtown Chicago is one of them. T-Mobile's new 600 MHz (band-71) licenses could help but Chicago is a very complicated TV market and the TV stations there are not scheduled to repack and clear the band until phase-8 (Winter 2020). It might be possible to squeeze a signal in between the TV signals before then. It's hard to say for sure.
About the only other card T-Mobile has left to play in markets like this is LAA in the 5 GHz unlicensed band (band-46). This is not without controversy because it's the same band used by 5 GHz WiFi. It would also have a range similar to 5 GHz WiFi (a few hundred feet). Only a few phones are currently available with band-46. Unfortunately, T-Mobile was "distracted" when the other carriers were scooping up high-band (>2 GHz) licenses and didn't get any.
In places like Chicago, L.A., B.A. & NYC it really pays to have a high-end phone with all-the bands, CA (Carrier Aggregation) and MIMO.