TMobile Engineer / Operations Support - TMO blocking email to text from sendgrid seriously impacting business

Hi, 
Tmobile just recently changed protocol about 10 days ago. We are an answering service and we’ve been seeing the majority of our messages to doctors, business owners, etc being blocked from Tmobile. Sendgrid is showing that Tmobile is blocking the messages in an effort to cut down on spam. All of our messages are legitimate. Sendgrid is trying to push us to using Twilio’s Text to Text API (which I suspect is because Sendgrid was bought out by Twilio and trying to get us to pay an arm and a leg for per text messaging rates). 

I need to reach out to t-mobile to determine how all of our messages can be added to a whitelist. Blocking our legitimate messages to our customers because they originate from email instead of text to text is seriously impacting our business and we need to find a work around for this asap. That or our only immediate solution will be to tell hundreds of t-mobile uses to switch carriers. 

I need to get a phone number or email to someone that has the authority to help with this issue - someone w/ TMobile’s engineer team - is there someone who can point me in the right direction on who to reach out to. The general TMO support line has been no help despite multiple calls and multiple messages that have amounted to - “don’t call us, we’ll call you...” and we have yet to hear ANYTHING back after a week and a half!