I find it difficult as well when people don't respond. When I'm adopting out rescues or selling chins, I often have buyers email me and I'll email them back with my adoption forms and such... and then I won't hear from them for a week. But you know, like Kristy said, we do have other things to do. I actually will give people a week (7 days) since the last time I sent them an email, and then I will email them, saying "hey, haven't heard from you for a week, just wanted to check in"... and for me, they get two more days after that to respond to that email that I send, and if they don't, I dismiss them... but you know, when I've sent that "it's-been-a-week" email, I have several times gotten responses saying that things have come up, and that the chinchillas are not on the top of their priority list when compared to fixing their car or repairing their roof. Which I understand...
...don't get me wrong, I still hate being left waiting. In fact, I sent someone an adoption form the other day and we're going on day 5 for them to respond. I have to say, that week of waiting to email them kills me! But I also don't want to turn into the pesty "how come you haven't emailed me back yet????" person. Patience is a virtue, and so few people have it anymore.
I'm not trying to defend the breeder you are talking about - I don't know them so I would have no reason to - but I just wanted to note.. you said the thing about you wanted them to say, "hey, this is happening..." and have them let you know what's going on. I mean no offense in saying this, but a lot of people that I know feel that it's none of other people's business what's going on in their lives. I'm told that I'm a pretty open person, but if I haven't been able to respond to emails in a few days because I was stranded in a snowstorm and had to stay in a crappy motel 10 hours from home for 3 days, or was taking the bar exam and wasn't near a computer for two days... I don't feel the need to explain that to someone, especially someone I don't know. Yeah, I've got good relationships with the people who adopt/buy chins from me, but for the most part (with exception of course), they're not my best buddies, and I don't feel they need to know every aspect of my life...
Just my two cents.