The right of a person to an annuity, the return of accumulated contributions, the annuity itself, any annuity option, any other right accrued or accruing under the provisions of this chapter, and all moneys belonging to a plan shall not be subject to execution, garnishment, attachment, the operation of bankruptcy or insolvency laws, or any other process of law whatsoever and shall be unassignable, except as is specifically provided in this chapter. However, an employer shall have the right of setoff for any claim arising from embezzlement by, or fraud of, a member, retirant, or beneficiary.