Aly, you said "that way if they've done anything "
They've already done something very wrong, TWICE..

I'm sorry to get so upset about this but every "standard
lease/rent agreement" should have a clause about
proper notification upon entering your apartment when
the tenant is not present..

Leslie,
Does your complex have a website ? Seems everyone does
now-a-days. Would need to see your lease/rent contract
to put a stop to this sort of thing. This is sooo wrong !