Where, for the purposes of rule 1.3.30 of the Rules for the administration of the Public Sector Superannuation Scheme in its application to a person who has ceased to be an eligible employee under section 245, the CSS average salary of the person has been ascertained by reference to an amount other than the amount referred to in paragraph (a) or (b) of the definition of CSS average salary in that rule:
(a) the person may, within 3 months after the person has been informed that his or her CSS average salary has been so ascertained, by writing addressed to CSC, revoke the declaration and election by virtue of which the person had so ceased to be an eligible employee; and
(b) on the making of the revocation, this Act has effect as if the declaration and election had not been made.