I worked a while in e-commerce and the default is that the money will be send back by whatever payment method you used in the first place. If you used PayPal, it will be PayPal. If you used money from your Steam wallet, it will be send back to your wallet etc.

Nope. Refunds can only ever be returned to the payment method which was used at the time of purchase.

This applies everywhere, not just Steam

引用自 scarecrow321：

Cause the last time I refunded something the game was removed but I don't think it got to my bank account

If you refund within a couple of days after purchase then the transaction is cancelled rather than being refunded as at that time Steam hasn't received payment yet. That's why a refund doesn't show, if you check your statement, you will see the entire transaction dropped off.

The last screen shot in Steam Support's article "How To Request A Refund" https://psteamhelp.yuanyoumao.com/en/faqs/view/784C-923B-A4A1-C825 shows "Refund to my Steam Wallet" and next to it is a white arrow that looks like you can click on it to get a drop-down menu where you can select either the original payment method or Steam Wallet.

And the Steam Store article "Steam Refunds" says,

You will receive the refund in Steam Wallet funds or through the same payment method you used to make the purchase. If, for any reason, Steam is unable to issue a refund via your initial payment method, your Steam Wallet will be credited the full amount.

https://psteamproxy.yuanyoumao.com/steam_refunds/

When you ask for a refund you ALWAYS get the option to refund the amount to the original payment method OR your Steam Wallet.
The Steam Wallet is selected as default since its a lot faster.

As for not getting the money back when send to the bank, if you refunded inside 24 hours after buying the game the money has never left your bank account.
All it had was a "hold", meaning the money was reserved for the payment to Steam.
If you refunded inside 24 hours the money was not sent yet to Steam and the bank will just remove the hold after a while.
Which means you wont see any transaction of refund money coming in from Steam since they never got your money in the first place.

引用自 scarecrow321：

If I bought a game and it didn't work could I have the game refund be sent to my steam wallet instead of my bank account

Yes.

When asking for a refund... the system will attempt to refund the original payment method by default. There's a small dropdown menu that allows you to redirect the money to your Steam Wallet instead. If you choose the original payment method and that fails, Steam will redirect the funds to your wallet.

If you paid with funds from the Steam Wallet, those funds will go back to the Wallet. You cannot redirect these out of Steam.

引用自 scarecrow321：

Cause the last time I refunded something the game was removed but I don't think it got to my bank account

Refunds that are initiated within a day or two of the purchase is usually completed by cancelling the payment from your payment method instead of a payment back to you. They simply don't collect the original payment.