Would you be upset at the mutilation of a present?

I gave a friend of mine a European square tin of international coffees, one day I asked
her how each of the four coffees tasted? She responded that her roommate just poured all the coffees together in one container that already had Maxwell house coffee in it and she shook it up. I was pissed off beyond words because that coffee was very expensive. Should I be angry or let it go because it’s hers and she had a right to do what she wanted with it?

Let it go. And don’t buy her another gift.

The thing that gets me is that it was the ROOMMATE who did it. WTF is the roommate doing in her gift?