If for any cause any person contributing to the fund who has served less than 12 years shall cease to be in the service of the City, he shall become entitled to the total amount of the contributions paid into the funds by him, without interest. Any person who has served for a period of less than 20 years, and who has not reached the age of 60 years, and who voluntarily retires from such service shall be entitled only to the return of his total contributions paid into the funds by him without interest. Except in the event of the notification by a member to obtain a limited benefit but in such event such person shall still be covered by the provisions of this section with respect to any refunds without interest.