This morning, I was relieved to have my phone number restored. I went in to the store and explained the situation. The lady looked at my account, swapped in a new SIM card, and restarted the phone. Within moments, it was displaying the correct number and receiving a test call and text with it.
Glad that’s resolved. I was worried that I might not be able to get the number back and would have a lot of work to change my number with every person and service, especially services that use it for second factor authentication.