@cathysyd Here's the deal with exchanges - they do take some time to process, weirdly too.
If you request an exchange, the replacement obviously has to be in stock and it very well may be AT the time you begin this process ie from sending back what you don't want to actually receiving the replacement.
If by the time the color and/or size has sold out you get a refund and a note/email saying what you want is no longer in stock. Yes it's a bummer but it's good when it does. They process your return and then seawrch, pull from stock the one you want. Mailing time makes this process slow, your return going back and then the new one going through the whole mail system again to get the new one to you.
So yeah, exchanges take a good while, and again bummer when it just cannot happen.