That requirement is absurd, since the other two don't show address either. No, this is just some arbitrary thing some wanker in HR has invented. (And to be honest, I'm not sure that they can require one of only those specific documents, legally - but you'd have to talk to a labour lawyer and probably wouldn't be a great conversation to have before starting).
That said: the easy route is just to show them that you have applied, that you have the other documents, and that it will indeed be mailed from Service Ontario in due course.
And sure, go to Service Ontario or call them, don't know what else to say. But so far (or at least in my limited interactions with them) they've more or less kept to timelines.