How long does it take for apple to refund card authorization money?

See this support document about card authorization holds. About payment card authorization holds in the iTunes Store - Apple Support They are not actually charges, and no money is taken out of your account, it is only a hold. This information may also help. iTunes Store charges on credit and debit card statements - Apple Support

It's your card issuer that should remove the temporary holding charge, how long it takes varies by card issuer - some only take a few days, other issuers might take a week or so