Q: Cancel a unredeemed Gift

Would I be right to think this refers to a gift card, purchased in another country and sent to you?   If so, the only way it could possibly be cancelled is by returning it to the sender, who would have to try and get the refund from where they bought it.   I doubt they would get a cancellation in any event because of the way these cards are sold, particularly from a retail store.

As you would have gathered, gift cards can only be used in the country of purchase, the exception being Europe, which is considered as one country. 

Then, no.  Gift cards are not eligible for return.