How can I fix iMessage and FaceTime verification issues?

I have two SIMs in my phone. One eSIM another one is a physical one. The eSIM is the primary one. Associated with Apple ID 2fa, Apple ID, iMessage, and FaceTime. For some reasons, I turned off the eSIM Settings> Cellular. After reenabling the eSIM iMessage and FaceTime, signed out. And asked me to reactivate, which I did. Since then, every few times it asked me to do so. Which cost SMS fees. So, I have reset and restored my phone. Still nothing, then I reset the network settings. Now iMessage and FaceTime are stuck in verifying. So, I went to my apple ID section, where my phone number is missing. I tried to enter the number, but no verification SMS came through. Then I tried the web (appleid). But, still, no verification SMS or calls from Apple. Already contacted my carrier; they said it was an Apple issue. I tried both cellular data and wifi. Still not available. I have been using this number and phone since 2019. 

Later, I found out that Apple releases any phone number after 30 minutes for security reasons. I dont get it, why 30 mis? All modern iPhones are dual SIM supported; all have a "Turn on/off this line" toggle, and I didn't delete my eSIM. Its still on the phone, so why does it need to be removed? Whatever security reasons, I can turn off/on a line for a few hours, shouldn't I? Isnt it the reason for this toggle Turn on/off this line," to exist? All this while, my phone was hitting this number: "447786205xxx." Incuring lots of SMS charges.

[Edited by Moderator]