No, they just change in their system the IMEI or ESN that phone number is registered to so all incoming calls and texts start going to the phone the attacker ow

No, they just change in their system the IMEI or ESN that phone number is registered to so all incoming calls and texts start going to the phone the attacker owns. It's just social engineering where you pretend to be the customer and tell them you need to transfer your number to a new phone.