Refunding bonds issued pursuant to § 13-51A-33 may be exchanged for the bonds to be refunded on a par for par basis of the bonds, interest coupons, and interest not represented by coupons, if any, or may be sold at not less than par, or may be exchanged in part and sold in part, and the proceeds received at any such sale shall be used to pay the bonds, interest coupons, and interest not represented by coupons, if any. Bonds and interest coupons which have been received in exchange or paid shall be canceled and the obligation for interest, not represented by coupons, which has been discharged, shall be evidenced by a written acknowledgment of the exchange or payment thereof.
SDCL 13-51A-34