I lent something to a friend for a while (several months) and I asked to get it back but I don't get it back. I asked again and again over the course of a couple of months, but the friend has various excuses (e.g. "I just have to find where I put it, but I don't have the time to do that.") and doesn't offer to pay me instead for the item's worth. This has gone on long enough that the friend gets aggressive when I bring it up ("I TOLD you you will get it back eventually!").
To the friend's defense I have to add that he really has to invest a lot of time into bureaucracy and health care to ensure his own survival (sadly I'm not exaggerating), but I know he also has time when he just relaxes (needed, I know), so I find it difficult to believe he really never has time to look. But I can imagine he simply lost the item somewhen and cannot admit it to me or himself.
So, despite his circumstances I find myself angry at him. I want him to know how strongly I feel. When someone takes something from me and doesn't give it back, that feels like stealing, even when the person talked me into giving it out of my "own free will".
How can I let him know how disappointed I am?