"Hi this is Zachary from Americollect. I'm a debt collector, and you can call me at 888-303-3634. I'm here Monday through Friday 7am-9pm, and Saturday from 8am-5pm. If you think I have the wrong number, please call me anyway to alert me of the situation"
Or something to that effect. The number on caller ID shows a 414 number, but the return number is an 888 number. Obviously, not calling.