A similarly-compromised front-line T-Mobile employee once enabled a "SIM-swap" on my active iPhone phone number.

It was reported in T-Mobile's systems as my personal visit, with supporting documentation/ID, to one of their retail locations in Oklahoma – thousands of miles from anywhere I'd recently been. So, while remotely possible that their employee gullibily-reviewed credible false documents, it seemed far more likely to be:…

- an insider abuse by a corrupt employee;

- a deep hack of T-Mobile's systems, allowing such admin actions with forged audit-trails; or…

- compromise of an authorized employee's credentials plus access to capable internal-system front-ends.

The Apple Support person I spoke to insisted that an analogous compromise here was impossible - that no Apple employee had the power take such an action without my Apple ID password. Based on other reports in this thread, I highly suspect she was lying to me, probably in conformance with Apple policy.