The US has phone-number portability.
You may be disadvantaged but that number can be transferred to a new phone.
Or, possibly, your existing phone at a new carrier.
https://www.fcc.gov/consumers/guides/porting-keeping-your-ph...
You may be disadvantaged but that number can be transferred to a new phone.
Or, possibly, your existing phone at a new carrier.
https://www.fcc.gov/consumers/guides/porting-keeping-your-ph...
AT&T is a incredibly consumer-hostile company that does not play by the rules, can and will hold your phone numbers hostage, and as shown here will arbitrarily disable devices when it is convenient for them.
File a complaint with your state AG's consumer protection office.
Most have a specific form (usually online) for telecoms issues.