>>267801034
Seems like the process varies wildly based on who you're talking to.
Mine took a couple exchanges, more because I was prodding for an advanced return, and wasn't able to get one.
Then shipping seemed to be a nightmare in that FedEx didn't pick up the package for days, and then took Valve another weekend to ship the replacements back out.

How much of that is just shit luck vs usual procedure is unknown to me.