2 factor authentication, I can't access because I changed my phone number

Hello, According to the explanation you have provided, I believe that you will need to submit an account recovery so that you can change your password and regain access to it. Click on this link and follow the instructions please: Help with the Microsoft account recovery form.

also note by doing the above you will most likely have to wait a while and remember alot of details and sometimes the account gets locked out, just a warning in case it does happen.

it is the account holders responsibility to keep their security and account details up to date, as you must have known your service was ending then changing or removing the 2fa number should have been done at that point.

it doesn't detect any problem, I have access to this account, but someone else is using it

You can change your password and enable 2 factor authentication.

If you have 2 factor authentication on it would require you enter a code that is sent to your cell phone number in order to login.

ive added my phone number as an verification and added 2 factor authentication

now what do i do and still gives me an error

I'm based in he UK and my phone number is from the same region. I've been able to use a code sent to my phone as a form of 2 factor authentication previously.