When the redemption is made to the treasurer he shall mark the word: “Redeemed,” the date and by whom redeemed on the margin of the book where the entry of the certificate of sale is made. He shall credit the amount paid to the purchaser named in the certificate, and pay the money to the purchaser, or his assignee, upon the surrender of the certificate of sale, and upon satisfactory proof of an assignment thereof, if the certificate has been assigned.