55. (1) Every sum certified to be due from any person by an auditor in his report under section 53, unless such certificate is modified or cancelled by the Administrator by an order made under section 54, and every sum due on a modified certificate shall be paid by such person within sixty days after the service of a demand for the same issued by the Administrator. (2) If such payment is not made in accordance with the provisions of sub section (1), the sum payable shall be recoverable as a public demand under the ¹[* * *] Public Demands Recovery Act, 1913.