T-Mobile has stores all over and they can help you cancel in person (I did this in the US, and it's very common to change carriers). I suspect you can also cancel online. You can also pay with credit card, and in extreme cases you can have your credit card company decline/block charges (I had to do this when Hertz tried to defraud me out of hundreds of dollars). I also suspect banks will happily decline/block charges as well, but I'm less sure since I route most of my transactions through my credit card--at the very least it's quite a lot easier to close a bank account in the US.
On the other hand, when I was in France just to open a cell phone account, I had to bring visa paperwork, proof of residence, and a bank account (no cell phone option) and it took 24 hours to open the account (compared with ~15 minutes + a credit card in the US).
I'm sure there are lots of things that are more difficult in the US, but France excels at bureaucracy in my experience. I should also note that I love France in general and its investment in nuclear power in particular. (:
Former Tmobile customer here. I ended up with an account on my credit report because tmobile never actually closed the account and kept right on billing me.
Twice. Once back in the late 90's when they were called something else, I think...and again a few years ago.
T-mobile stores are explicitly forbidden to help you cancel service. At the branch I visited, they insisted they were physically unable to cancel anything. It is possible they were lying, but equally possible that corporate did make it impossible for them.
We tried to cancel my mother-in-law's account. Even after they got a copy of the death certificate, they still refused to cancel.
About all you can do, usually, is cancel the credit card they are deducting from, or maybe to get your bank to reverse their charges and refuse any new ones. Do not ever give T-mobile rights to charge for your account, monthly.
So strange. Just before the pandemic, I went into a T-Mobile store and cancelled my hotspot service. No problems. Perhaps it's a regional thing? Or a performance issue for a particular store?
On the other hand, when I was in France just to open a cell phone account, I had to bring visa paperwork, proof of residence, and a bank account (no cell phone option) and it took 24 hours to open the account (compared with ~15 minutes + a credit card in the US).
I'm sure there are lots of things that are more difficult in the US, but France excels at bureaucracy in my experience. I should also note that I love France in general and its investment in nuclear power in particular. (: