[newjersey]

Kept getting bills every month even though I had cancelled and I was supposed to be on the free for life plan of 200MB. The representative acknowledges it was their fault every time. They removed the item from the bill every time within fifteen minutes of me dialing.

Then I changed address. They might still be billing me for all I know.

[jerf]

If you are in the US (reasonable guess for a(n ex-)T-Mobile customer), you might want to exercise your right to pull a free credit report check and make sure it's not screwing it up.

Since it is actually a bit challenging to correctly pull your free credit report, start here: https://www.ftc.gov/faq/consumer-protection/get-my-free-cred... (Simply Googling "free credit report" and clicking willy-nilly can lead to sadness.)

In fact I'm overdue to pull mine myself; thanks for reminding me.