The certificate issued to the witness entitles him to demand, of the party summoning or at whose request he attended, the amount therein stated and is presumptive evidence that such amount is due in any proceeding instituted for its recovery; and, if in any civil case, on demand therefor of the party, his agent or attorney, the same is not paid, the witness is not obliged to appear again as a witness in the same case until his fees are paid.