Should a person receiving a superannuation retirement allowance or an involuntary retirement allowance or a total disability retirement allowance be reemployed by the city, the retirement allowance of such person shall immediately cease. Such person shall thereupon be reinstated as a contributor, and there shall be restored to his credit as accumulated deductions the actuarial value of his member's annuity computed as of the date of his reemployment. Should he refuse to surrender his right to retirement allowance as of the date of his reemployment, then it shall be unlawful for the city to reemploy him.
53 P.S. § 30572