I would be addressing it with them as well.. And if my kids were served UHT milk, I wouldn't be concerned. They drink it when we are on holidays and don't have access to a fridge. But they have offered to supply it.. What I don't understand is why they can't just say that they can't supply it, and can you start sending it in, cause it seems that you are happy to do so..

We send milk for DS as he has A2 milk. He can drink normal milk, but we prefer him to have this and I know there is no-way they would supply it for him.. on occasion, they have slipped up, but thankfully for us, it is a preference, not a health concern.