With the bank teller thing, here is what I suggest.  Come prepared to the bank, and when you are the next in line to be served, have a lot of papers with you and stand there fiddling with them like you're organizing and give the "one moment please" finger to the teller who is waiting to serve you.  Then have a cell phone with you and have someone phone you at that exact minute, pick up the phone and then produce a sign that says "next customer please".  This will make the teller and all those behind you angry and confused but slightly bemused.