T-Mobile now lets you chat with customer support in iMessage
https://www.theverge.com/2018/4/11/17226452/t-mobile-now-customer-support-imessage-business-chat
T-Mobile has announced that through an update today, it is now supporting Apple’s Business Chat. Included in iOS 11.3, Business Chat is a way for customers to chat with company reps over iPhone, iPad, Mac, and Apple Watch. That means instead of calling, emailing, or hitting up Twitter DMs and Facebook Messenger when you have a question, you can talk to an actual human being at a company directly through the iMessage app.
Though T-Mobile already offers the ability to chat with representatives through its app, more ways (and certainly, more streamlined ways) to get a hold of a company is never a bad thing. T-Mobile says it’s accessible through Maps, where a “Message” icon will appear when you click on the listing for a T-Mobile location, and by typing “T-Mobile” into Spotlight on your phone (although when I tried this, it did not work). Once you tap on the message icon, you’ll be taken to the iMessage app to start a conversation.