Hi
Thank you for contacting AT&T through Community Forums! We would really hate to see you go but we are definitely here to help!
To cancel wireless service, you can reference the article on the AT&T website – Cancel wireless service or remove a line.
You do have access to the AT&T International team which can be reached toll free from your personal AT&T mobile device. That toll free number is +1-916-843-4685. In most devices, the (+) sign appears by pressing and holding down the 0 key.
Hope this helps!
Tim, Community Specialist