Is the amount paid by a person to charge a card for adult channels—without the recipient's knowledge—considered a debt upon him, or should he donate it as charity?

What the man did is a sin, and his wage is unlawful. Therefore, he deserves nothing for his work. It is not permissible to pay him this wage because he is not entitled to it legally, as the contract involves a prohibited benefit. This is what Imam Al-Tabari stated in "Al-Kafi." You both must repent and cut off the forbidden channels.