How to Remove or Reinstate 2FA Google Authenticator

I am a prepaid plan user and set up a 2FA method through Google Authenticator (GA) when registering my T-Mobile account. As setting up, I received an email stating:

"If you didn't make this change or want to remove this feature, please visit us here. If you have additional questions, please visit us here to message or contact Customer Care."

I thought I could get help from T-Mobile if I encountered any problems with this 2FA method.

Unfortunately, I lost the device that stored my Google Authenticator codes, and I don't have a backup. I want to remove or reset the GA method tied to my account. I've contacted several customer service representatives about this issue, but none have been able to help.

Although I can log in to my account using a different two-factor authentication method, such as SMS, I still want to remove or reinstall the Google Authenticator method. This is because if someone gets access to my lost device, they could potentially use the GA method to sign in to my account.

I have noticed that many websites, such as banks, allow customers to reinstate their 2FA methods. I want to know if it is absolutely impossible for me to change the GA settings on my T-Mobile account.