I order from mail order all the time. I always ask for a supervisor if the person taking the order is nice and takes the time to talk with me. Too many persons do not let anyone know that these hard-working persons have a clue about the products and customer service.
It's people like you who take the time to do that that makes it all worth it. Whenever a customer would let my supervisor know that they appreciated what I had done for them, I would generally let them know how much I appreciated their kindness by either calling them to say thank you, or by sending them a thank-you card.