is it possible to report slow speeds?

For the past 2 months I've been dealing with download speeds of zero to 5mbs during weekdays Mon-Fri. If I have anything above 2mbs, I can get a cell signal to report problems. Today it is 1.4 mbs and no cell service even with wifi assist. I can only make SOS calls, otherwise I see "dead zone". I can't chat with support as I don't have enough bandwidth. 

Even right now it took 3 min just to load and log into this page. 

Ive tried reporting poor service once I can get back to 4mbs but they just tell me all is good on their end and it's congestion. 

Anyone have an email address that I can use to report very poor speeds? Or does TMobile not even care that on Mon-Fri from 8am to 6pm, when I need it most, my phone and TMHI is extremely poor, unstable and unpredictable.