In the event of termination of employment other than as a result of transfer to another public employer, a member participating in the retirement plan provided for in article 14 of the Retirement and Social Security Law, who is not vested or entitled to any other benefit under article 14, may withdraw his CO-ESC contributions and terminate his membership in the New York State Employees' Retirement System by filing a form prescribed by the Retirement System for this purpose. Such a request may be made after the member has been separated from service for at least 15 days. The Retirement System shall thereupon refund the CO-ESC contributions.