Blimey, it sounds as if they are trying to pinch your bike bit-by-bit.
I agree that the best remedy is a good dusty hack bike, I am often puzzled as to why people take their pride and joy into town and leave it bolted to a tree all day, either they should buy a bigger lock or a cheaper bike for the commute.
The fact that you know this is "ongoing" must be a massive frustration to you, and would make me fell pretty paranoid, or at least make it difficult to think of much else all day except, "will my bike be there tonight and will it work properly if it is!!"
Good luck sorting this. Hack bike is the way to go
Jonny