Whenever the board determines that (1) any person has knowingly made any false statement or falsified or permitted to be falsified any record or records of the retirement system in an attempt to defraud the system, or (2) any person who resumes employment with any governmental entity or accepts, directly or indirectly, work on a contract basis from any governmental entity, except as provided for under this article, the board shall terminate any benefit that a person is receiving, has received, or is entitled to receive under the early retirement provisions of this article. Further, if any person taking early retirement under this article desires to revoke his or her early retirement incentive, he or she shall be allowed to do so if he or she is entitled to regular retirement pursuant to this article: Provided, That such revocation shall be retroactive to the date of last employment and any incentive annuity already received by the retiree be repaid to the retirement system. Any person who revokes his or her early retirement incentive shall be thereafter carried upon the records of the retirement system as a regular retiree and shall not be entitled to any enhanced benefit by reason of the early retirement options contained in this article: Provided, however, That any person who opted to retire pursuant to the early retirement provisions of this article who would not have been and is not eligible for regular retirement but for the early retirement incentive options must upon returning to the employment of a participating employer, reapply for admission to a retirement system and repay all pension benefits paid to that person since the date his previous employment ceased. Any termination of benefits may be appealed pursuant to the state administrative procedures act in chapter twenty-nine-a of this code. The board shall promulgate rules regarding the procedure for termination of benefits and the repayment of any benefit, in accordance with the provisions of article three, chapter twenty-nine-a of this code.