First, check the by-laws to see if rules about the storage cage is mentioned specifically. If it’s not, I’d be leaving my stuff there until someone asks you to remove it. But to be fair, label it with your name, apartment number and a way of contacting you. Also you shouldn’t really be taking up more than 1/21 of the space. No one should dispose of your property without giving you 28 days notice (I found this out from a Fair Trading web page after a tenant moved out of our building, leaving us with piles of whatever stuff he didn’t want to take with him).