I'm always amazed when I hear statements like this. If my customers called and i told them to keep this in mind, they'd think I'd flipped my lid. Seriously, when customers call (and one in five isn't a bad ratio BTW), they don't care about anything but the product, that requires giving information.
Most companies have websites etc., in your line of business, it's sometimes more of a personal connection over the phone that seals the deal...bear this in mind.
I understand that there are frustrations in business, any business. Suck it up, you chose to be in business for yourself so deal with it. The rest of us who own businesses do.
Sorry to single you out, but this goes for all the SP's whining in this thread.
Flame away!