An employee who received a refund of deductions from the Illinois Municipal Public Utility Employees’ Annuity and Benefit Fund, and subsequently becomes a participating employee under this Article and renders two years of contributing service, may pay to the Fund the amount of the refund, including any interest received, plus interest at the effective rate for each year from the date of payment of the refund to the date of repayment. Upon payment, his service under the Illinois Municipal Public Utility Employees’ Annuity and Benefit Fund shall be established as creditable service under this Article and the payment shall be credited as normal contributions to his account.