If someone takes something of yours without asking

And you only find out when you need it (humidifier, not something you use everyday hence you didn't notice earlier it's gone), do you at least expect a "sorry" when YOU have to go ask for YOUR stuff back?

I am very sick and someone who shouldn't even be here just took it out my cupboard to use in their own part of the home. I have been coughing my lungs out for two days now and they haven't even offered it back, I had to ask them today if they have it and they just gave it back, not a word about it. I'm a little peeved.