How do I turn off billing text messages like this?

If you have line access granted you can turn most sms messages from your MyTmobile account if it's a post paid account.

How exactly would I change it? If I navigate to Profile > Privacy and Notifications > Notifications, I see a section for Text notifications, but it "says always" on with no option to change it.

The primary account holder probably needs to change it.

I am the primary account holder and I still can't change it.  I see the same thing as FireMelon and want to not receive these messages.  I don't care about them, and they clutter my life.  ¡Gracias!

There's some sms from Tmobile that can't be turned off so this maybe one.

Thanks for the info, but that's a bummer.  I don't like being bombarded with text reminders, etc, from businesses and like to choose when and how I am contacted.  The text ding-dong for something I don't care/worry about is really annoying.

I just set up a Pixel watch and now my notifications go there and I really don't notice them and nothing on my phone.