Hi there! @Barbara29 thanks for posting your calling concerns.
I’m sorry to hear you’ve had issues with this. You should absolutely be able to place and receive calls in Japan with the AT&T global passport without any other services on your account. You’ll want to dial a number there just as you would from a local phone in Japan.
To place a call or send a message back to the U.S., simply dial + (1) (area code) (number).
To call or send a text to another country from Japan, dial +, followed by the country code and local number.
If you are unable to do this, try turning your phone off for 2-3 minutes and try again once your phone registers with the cellular network there.
Thanks!
Charise