Unable to register as the PAH

I'm having this same exact issue. I have called customer support and they said I had to take my social into the store and have a T-Mobile rep confirm it before they could fix it. (I did not have this issue until I added a second line). Once in store, I explained what happened and a rep called customer service to explain why I was there. After explaining my situation once again, they told me that there was nothing they could do and I had to write a letter to T-Mobile in New Mexico (I took my ID, Social security card and birth certificate to the store, how could they not help!?). Snail mail is ridiculous when anyone can write a letter and claim to be me. It's different when you show up with a photo ID, birth certificate and social security card. I went home very dissatisfied and disappointed with the lack of customer service I received in store. I called the CSL again and was told I had to go back in store and take my documents again and the reps had to call them, then be redirected to consumers credit department (where they should be able to fix my issue). I would have never left my last carrier if I knew this was going to happen. So far no resolution for my own account that I created and pay the bill for. Ridiculous. I feel for everyone experiencing this same issue. I'm amazed at how some got this resolved in a matter of minutes.