This is why 2 factor authentication via text message is very weak. My phone number has been compromised, as it's been leaked and all the scammers have it.
They have all my personal details, and can easily call my phone company and fool one of the representatives to swap my sim to their phone. Once that happens, they just log into my bank account, get the sms authentication code, and log into my account.
That's why I'm going to get a new 7/11 speakout sim card and use that number to tie to all my important accounts for 2 factor authentication. Since it will be a fresh number, no one will hack it.