(A) All officers and employees of the city shall be members of the retirement system, except persons whose services are compensated on a fee basis, and persons whose compensations per annum for services rendered to the city average less than an amount to be determined by the Council. In all cases of doubt as to any employee's membership status the Board shall decide the issue.
(B) Provision shall be made that, except as otherwise provided in this chapter, if any member leaves the employ of the city for any reason, except to retire with a pension payable from retirement system funds, he shall thereupon cease to be a member of the retirement system and he shall forfeit his credited service. He, or his legal representative, shall be entitled to the return of his accumulated contributions standing to his credit in the pension savings funds. In the event the said person returns to city service he shall again become a member; and should he return within a period of years which is not greater than the number of years out of city service, his service credit forfeited by him at the time he last left city service shall be restored to his credit provided he returns to the pension savings fund all amounts he may have previously withdrawn therefrom, together with interest thereon.