Website address: https://www.t-mobile.com/
Phone Number: (800) 318-9270
Email/contact form: investor.relations@t-mobile.com
Facebook page: https://www.facebook.com/TMobile/
Twitter account: https://twitter.com/TMobile
Mailing address: T-Mobile US, Inc., 12920 SE 38th Street, Bellevue, WA 98006