About Calls

[Shin]

My account shows calls are unlimited.

But when I call, it says I need to charge account balance, because it’s too low.

So I changed it a little, and try to call. 
But While I’m calling, the device stop to connect and say the same thing above. 

My device is unlimited for calls, right?

[kelper]

Unlimited does not apply to premium rate or overseas numbers.

[JonathanB]

Hey Shin,

Welcome to the Three Community.

As kelper says, Unlimited calls don't apply to premium/international calling. When you have a PAYG add on, you can use the Unlimited minutes to call UK landlines and mobiles only. 

If the number you're trying to call is a standard landline or mobile, I'd recommend opening a chat with the PAYG team here. 

Hope this helps,
JonathanB