I had a similar issue, and I still wonder how I could/should have dealt with it?You're being facetious, but in certain infantry battalions theft was a serious problem. It wasn't confined to private soldiers either.
As a young soldier I had some items of privately bought kit stolen by a JNCO. His attitude was "What are you going to do about it?"
When it came down to it, there was precisely nothing that I could do about it.
I lent a colleague a item of clothing, and he just point blank refused to give it back.
We were the same rank and he was a nasty little Brummie, and I don’t mind admitting, that he may well have won in a scrap.
It felt too trivial to bother my superiors over a £30 shirt, I didn’t want a fight and so I just felt that I had to write it off.
Still annoys me, many years later.