It probably varies based on item price and how obvious the issue is. I had two sub-$10 items arrive visibly broken recently and got refunds in under 5 minutes.
You have to call their bluff when they try to pull that, they don't want you to ship stuff back either. I got a full refund after a few back and forths of "are you sure you want to ship that back for a refund??".
Hmm, with one exception, every time I've had an issue it was resolved with a full refund within 5 minutes. They do make you give them a picture of the issue.
