When our shipment of baby chicks from MM arrived, we got a call Monday morning, 7 a.m. Not a one of them (50 chicks) had any feathers to speak of, and all still had their egg tooth. Yours sound a little older, and I really think they were in transit too long.
Their catalog states you will be given a refund or replacement (your choice) for chicks that have died within 48 hours of arrival. That's why the lady wanted to wait to see.
It is always possible that a postal employee doesn't know the protocol and puts a box of chicks in a postal truck, or leaves it on a loading dock, or who knows what. Mistakes happen, unfortunately.
I'm sorry you had to find your chicks in this condition.
Nop169, I wouldn't knock them for a callous attitude. We get bothered by things, like sick or dead chicks, sick kids, dying pets... but the people who work in those fields see it ALL THE TIME. And just like the people on this site, some people come across as more sympathetic than others. You can call ANY company and get either a very nice person, or a very rude person. It just depends on who answers your call. But I'll bet MM doesn't have any rude people working their phones. They are just very used to receiving calls from distraught people, so it's not a big deal to them. I don't think I could ship chicks all over the US with a 100% live rate, and I sure couldn't deal with the distressing phone calls. I give legitimate hatcheries credit for their efforts, personally.