Any former sheriff of Butler County who is forced to withdraw from any retirement system in which he or she was a member and who by virtue of being a member of such retirement system was required to pay both the employer's and the employee's share of contributions, shall have refunded by the county all personal contributions as hereinafter provided. The county commission shall refund any contributions not previously refunded by warrant drawn on the county treasury in the same manner and under the same conditions as any such previous refund.