Any person who is overpaid any amount as benefits under this part is liable for the amount overpaid unless:
(a) The overpayment was not due to fraud, misrepresentation or wilful nondisclosure on the part of the recipient, and
(b) The overpayment was received without fault on the part of the recipient, and its recovery would be against equity and good conscience.
(Added by Stats. 1955, Ch. 1153.)