7. In the case provided in section 4, where the contributions paid by the person during the year of leave are more than the contributions required under the retirement plan to which he contributes in order to credit a year of service or part of a year of service for each year or part of a year during which he received only part of his salary, the difference shall be refunded as overpayments in the manner prescribed by that retirement plan.
The person may redeem the year of leave or part of a year of leave in accordance with the provisions of the retirement plan to which he contributes respecting the redemption of a leave without salary.
O.C. 1863-83, s. 7; O.C. 1773-86, s. 1.