Are you seeing this on a past bill or current bill?
The specific legitimacy in the link may not be specific to you, but it explains what the service is or was. Sprint and Verizon also had the same charges and issues against them.
Hey cwillett722! The Premium Text Message Refund Program (sometimes referred to as the T-Mobile Premium SMS Refund Program) has now ended. The purpose of the program–which ran from July 14, 2014 through June 30, 2015–was to refund customers for any unauthorized premium text message charges in the past that were not already fully refunded by T-Mobile.