Of course it's not their fault, I appreciate that. I would just like to have control over a system I've paid for - maybe I am just a control freak, lol.
Regarding insurance, I didn't bother telling the insurance company about the alarm, as it reduced the premium by the grand sum of £12. Seemed to make more sense to spend the £12 extra, than have the insurers able to decline a claim because someone had forgotten to set the alarm when we went out.
Looks like I'll arrange a maintenance visit then, the batteries probably need changing across the system anyway - are they all meant to be changed annually?