I will guess that a class action is off the table because they imposed a mandatory binding arbitration clause (yup, https://www.t-mobile.com/responsibility/legal/terms-and-cond...). And forced binding arbitration is legal because the Supreme Court seems to be owned by corporations and billionaires.

I suppose we could file complaints with the FTC and the FCC, but I suspect it will not help. After all, they probably got thousands of complaints about Comcast, but that didn't prevent Comcast from taking over the media world.

T-Mobile used to be one of the better ones. But it was probably inevitable that they would succumb to the enshittification process that is devouring the corporate world.