What the....?? That is awful!
I also understand the need for checking for drugs, but quite honestly there are BETTER ways to do that than destroying the item like this! This is not OK. By a long shot. I would have been so sad too, and then I would have been truly really mad. Please send in a complaint to the customs, hon. This is not the way to go about checking for drugs - it is just taking to much liberty in their line of work and no respect for what is actually others property.
Yeah, I have to stop myself now I think because I'm just so mad and sad on your behalf....
I am happy that the seller will send you a replacement though, that was very kind of her!