You can argue that you WOULD explain it to tennants and put it in the lease - but you weren't shown the lease and therefore didn't sign it. You're out of aaaaall the hassle that way. (And yes, I'd expect a conventional system too as a renter, but a different one wouldn't bother me if I knew how to work it.)

To be honest, I'd put in a complaint with the manager and get a different property manager. Different company if you had to. I'd be very unhappy with your current one as she can't do her job.