The total exemption under § 58-12-6 of benefits presently due and payable to any annuitant periodically or at stated times under all annuity contracts under which he is an annuitant, shall not at any time exceed two hundred and fifty dollars per month for the length of time represented by such installments, and such periodic payments in excess of two hundred and fifty dollars per month shall be subject to levy in the manner provided by law and the rules of court.
SDCL 58-12-8