I am new to chickens and went with meyer's as at the time they had many varieties of chickens available. I ordered 18 chickens that arrived on 5/20. Two were missing and four of the six bantams ended up dying. There was also only nesting on the bottom and lots of air holes punched out, so I believe they got cold. Called and they offered to refund/replace the ones that were missing. They arrived 5/28 and none of those died. I have a pending duck order through them for next week, but I'm throwing around maybe canceling it and going with someone else. Next year if I order more chicks I will be going with a different hatchery.
What state are you in? Personally I would go with whichever reputable hatchery is nearest to you. We chose Meyer because they are an hour drive away, though I've heard their chicks arriving safe and sound in Hawaii (probably get there faster on the plane than they do a couple states over knowing USPS. Either way most hatcheries aren't going to send heat packs in May, but I am sorry to hear about your poor experience. Maybe also look into nearby breeders.