steam refunds

I've only had it refunded to my wallet. I think you can have it refunded to your card, but I've never bothered.

You can ask to get the money on your Steam Wallet. That's what I do when I ask for refund

It's your optional choice when asking refund, to steam wallet or Credit card =))

I think that if you bought something with credit card you can choose to refund the money on the credit card or steam wallet. If the money were from steam wallet they go back to steam wallet.