Can you purchase games using money redeemed on two shared accounts?

You can't use money from two different accounts at the same time. You would need to try contacting support to see if there is anything they can do so maybe you can redeem the money to the correct account. 1-800-4my-xbox if you're in the US/Canada or
support.xbox.com/contact-us

Hi, yes. Redeem the code here and the purchase the game using the link shared below.

The $10 value is going to remain in your Microsoft account. So you can use the money later or purchasing something else with that value or less

Codes are one time use only. Since you already redeemed the code on another account, you would either have to purchase it again for the account you want to use, keep using the other account, or set your console as your Home console on the other account so
you can share the game between the two accounts.

As smwutches mentions, you cannot transfer the money between accounts.

However if I the same region, you can use the money to purchase games as gifts you can redeem on your other account.

Or if you shop at microsoftstore.com you should be able to use your account balance to purchase another gift card to redeem on the correct account. This may vary by region however.

There is no way to get a refund, as it was a gift card, and there is no way to transfer it to another account. Is this gift card just money, or virtual currency for a game? If it is just money, then you can still purchase games with it, by purchasing the game as a gift for the account you want the game on. If it is virtual currency for a game, then there is nothing that can be done to move it to another account, so your only option would be to use it on the account you redeemed it on.