40 ILCS 5/19-215
Any employe who has been contributing to said fund, and who shall be dismissed or resign may, upon application receive the total amount paid into said fund by such person so dismissed or resigning plus interest at the rate of 4% per annum to the date of such dismissal or resignation; provided, however, that no interest shall accrue or shall be paid on such amount in the case of any person becoming an employe and a contributor to this fund on or after July 21, 1947.
Any present contributor to this fund who shall have received a refund of prior contributions from this fund may at any time prior to July 1, 1959, repay to this fund the amount of such refund together with interest at four per cent per annum from the date of refund to the date of repayment, and credit for such length of service shall be restored.
40 ILCS 5/19-215