This text message is the fake scam link people click on before discovering a bunch of card fraud and having to call their bank to dispute a charge. Do not click that link. Call T-Mobile using their official phone number online and verify it's not a phishing attack before doing anything.

Edit. People in the comments saying it's legit. If true, TMobile chose the shadiest way to send these messages out. It's just good practice to never click on unsolicited links before making sure it's not phishing.