Dad is primary account holder

So about 5 yrs ago, my dad became the primary account holder when a (likely Asian) T-Mobile associate approved it without my consent. He told me after the fact because it'd save us about $10-20/mo. Fine, no problem.

Fast forward to January 2020, Dad moves back to Taiwan and I lose touch with him. Now I'm stuck with no way to get my account back because I'm no longer the primary account holder and I have no way of getting in touch with him. The T-Mobile associates I talked to all say I need to get his permission. This was originally my account for 8 yrs before he was added on (I was solo) and now I don't know how to take back my account?

to add: The reason why I believe it’s an Asian associate is because my Dad’s English is subpar at best and my stepmom had MY credit ran (also without my consent) by an Asian associate years prior to this when they went around shopping for family plans.