Also, when cancelling a subscription service tell them the reason why you're cancelling is because you're moving overseas.
When I did that in the UK (when I was moving overseas, as it happens) I found that it was a really effective way of bypassing all the usual retention nonsense and, i'd presume, any follow-up calls. If you're moving out of their service area, there's literally nothing they can do to keep you on their service.
It is fairly non confrontational (especially to the voice on the line) and a very direct signal that you are a dead lead.