Whoa, it binds with 38s too? Does the case go all the way into the chamber so that the rim touches the cylinder?
Either that cylinder is too long, or the frame is uneven behind it. The case heads are catching on the frame behind the cylinder, right? I bet it's the cylinder. Oddly, I can't find any place that sells cylinders for any of the 600 series revolvers. Wonder why.
Anyway, this is only for my own curiosity.
You're going to have to politely and firmly explain to their customer service that they could not have investigated the problem you described, because it persists, and it's very obvious, and very easy to test. When you send it back this time, fill the chambers with empty, unprimed cases, and bind that sucker up good. Mark the frame and the cylinder so you know if they touched it, and maybe even the cases, too.
I'd also take pictures of the gun to see if they send to the Chip and Nick, the ham-fisted revolversmiths. But that's just me, and I like a good argument.