Are you buying from the UK bookdepository or the US one?
I've been buying comic Trades from the UK one for a few years, and every time they are packed tightly in either thick cardboard A4-ish envelope (most often) or a padded bag (rarely).

I've always been impressed at how those cheap purchases end up arriving in mint condition, preventing me from ever having to shop locally.
Amazon on the other hand - should have at least wrapped up the comics in a little bit of plastic (like a sandwich), just so that they at least slide around as one big brick... preventing them from sliding into each other.