Countries that do not accept foreign exchange will not give you a tax refund for nothing, so they will not write you off.

Even if something is broken, it should be returned for repair before export. If they don't need to return the goods, it means that the maintenance cost is higher than the value of the goods, then there is no way out, which is equivalent to giving them to others for free. Free things can't be written off ~ ~

Still in a word, foreign exchange cannot be written off if it is not received.