1. The plaintiff's appeal is dismissed.

2. The costs of appeal shall be borne by the Plaintiff.

The purport of the claim and appeal is the purport of the appeal.

1. The reasoning for this part of the reasoning is the same as that of the judgment of the court of first instance, and thus, this part of the reasoning is cited in accordance with the main sentence of Article 420 of the Civil Procedure Act.

2. Judgment as to the main claim

A. The gist of the parties’ assertion 1) The Plaintiff’s representative director asserted for the cancellation of the causes for non-performance refusal, which, around the time of the dispatch of the first and second peremptory notices, failed to comply with the request for change of address because it is difficult for the Defendant to perform in the hospital, despite being informed by telephone. On July 13, 2017, the Defendant visited the Defendant to extend the payment period by approximately four months, even though the payment period had already been extended, and expressed his/her intention to refuse performance that the existing payment period could not be met.

As such, the instant sales contract was lawfully rescinded in accordance with the instant rescission notice dated July 27, 2017, since there was a refusal of performance.

In particular, the Plaintiff’s representative director visited the Defendant on July 13, 2017, and received the first and second peremptory notices to express his/her intent to refuse performance. As to such refusal in favor of the Plaintiff, even if a grace period of 30 days under the instant sales contract is recognized, it shall be deemed that the instant sales contract was rescinded on August 13, 2017, where 30 days have elapsed from July 13, 2017, even if a grace period of 30 days under the instant sales contract was granted to the Plaintiff.

B) (1) The Plaintiff did not comply with the payment period of the first intermediate payment, and the Defendant sent the first peremptory notice on May 25, 2017, but did not pay the first intermediate payment for the lapse of 30 days thereafter, thereby losing the benefit of time. Accordingly, the Plaintiff did not perform the contract even though the Defendant sent the second peremptory notice on June 27, 2017 and notified the cancellation of the contract without paying the purchase price within 30 days. Accordingly, the instant sales contract was canceled on July 27, 2017, when 30 days passed from June 27, 2017. (2) Article 10(3) and (4) of the instant sales contract.