1. The judgment of the first instance is revoked, and all plaintiffs' claims are dismissed.

2. The plaintiffs' total costs of litigation.

1. Determination on the cause of the claim

A. 1) The facts of recognition A and Sam Young Construction (hereinafter referred to as “the Plaintiff side” in total

(2) On May 28, 2009, the part of the construction among the new construction of teachers of the Ulsan Foreign Language High School and the part of the site suspension work (hereinafter “instant construction”) by dividing each share by A51% and 49% among the Administrator of the Public Procurement Service on May 28, 2009.

(B) the contract agreement (hereinafter referred to as “instant contract”).

(2) The Defendant is an end-user institution that is obligated to pay the price for the construction contract concluded by the Administrator of the Public Procurement Service pursuant to Article 2 subparag. 4 and Article 5-3 of the Procurement Act.

On the other hand, on April 1, 201, A filed an application for rehabilitation with the Gwangju District Court 201Mo12, and on May 12, 201, A received a decision to commence rehabilitation and to appoint Plaintiff B, C, and a decision to authorize rehabilitation on December 19, 201 from the above court.

3) The Plaintiff received both advance payment and payment for completed portion once through seven times, as indicated in the details of payment for completed portion, according to the progress of the instant construction project. After the Plaintiff’s inspection on January 14, 201, the Plaintiff claimed KRW 2,790,716,950 to the Defendant at that time. However, on February 1, 2011, the Plaintiff received only KRW 1,500,000 out of the completed portion, and on May 2, 2011, received the completion inspection on April 9, 201, and claimed KRW 9,401, KRW 401,439,490 to the Defendant, but not yet received the payment. According to Articles 39 and 41 of the General Conditions of the instant Construction Contract, the head of the end-user institution, and the head of the end-user institution, within seven days from the date of inspection, made a final and conclusive payment to the contracting party.

[Ground of recognition] Facts without dispute, entry of Gap evidence 1 to 5 (including each number), the purport of the whole pleadings

B. According to the above facts of determination, the Defendant’s payment for completed portion of KRW 1,290,716,950 for the eight-time payment for completed portion (=2,790,716,950 won - 1,500,000 won) and the payment for completed portion of KRW 401,439,490 for completed portion for the nine-time payment, barring special circumstances.