Q: 5S cellular data network could not be activated-PDP authentication failure

Iphone 5S could not activate cellular data network due to PDP authentication failure.  Phone was used in Japan (B mobile service with NTT DOCOMO chip), taken to US for 2 months (T mobile service), and now back to Japan with same B mobile service chip installed (monthly service was paid for and maintained for 2 month period while in US).  Some setting was altered by Apple Employee in the US to make phone work with T Mobile chip.

Latest IOS 9.3.1 version

Have tried Hard restart, taking Sim card in and out, reset network settings, switching cellular settings off and on, switching carrier setting from automatic to manuel.