selective theft

I have a so called "day-subscription" for the Standard, i.e. I only get the newspaper on one day of the week. I deliberately chose Friday as this is the day when you get their free RONDO magazine. When I leave for work on Friday morning, I find the newspaper waiting for me on my doormat. So far, so theory. On the last few Fridays, however, that meant the paper minus the RONDO supplement. I suspect one of the owners of the 4 penthouses as I never had this problem before the roof was adapted for posh duplex apartments. Not wanting to get up at 5 a.m. and peek through the peephole until the RONDO-thief does his dirty deed I've contemplated writing a sarcastic poster for the notice-board. Or could it be a new advertising coup of the Standard people themselves, deliberately pissing off subscribers with a brainwave along the lines of "our supplements are so good they get stolen before YOU get the chance to lay your hands on them". Who knows.