I completely disagree...I sell tons of shrimp and other aquatics. I have a very busy life and selling aquatics is not my primary function. I think it is very reasonable to give someone a week. Sure I try to get back to people in 3 or so days, but to say 48 hours is kinda of ridiculous IMHO...I am not some big corporation with a customer service department. Sometimes it takes me an entire evening just to get through half the emails I deal with every day.
Steve...give him a week, if nothing then, go right after whomever it was.
I don't buy that.

No offense. I'm a VERY busy person myself, very type A with lots going on. I work a "real job" I have a few social obligations, two children under 5, my husbands business I co-own, my own Etsy store, avid crafter etc AND a broken leg, and yet I'm still able to answer emails in a very timely manner. (IE within a few hours of receiving the initial email/contact.) (Plus I manage the household duties, ie "wife/mommy" stuff! Cooking, cleaning etc!!!)
If you have time to POOP you have time to answer an email.

When peoples money is involved and my reputation? You bet my bottom I'm on the ball with responding to a customer with a problem OR an order question.
That is just me however and how "I" choose to operate.