지명채권양도 후 기본관계가 해제된 경우 부당이득반환

Who is the profiteer when the original contract between the assignor and the obligor is cancelled after the obligor has paid off to the assignee?

In case, after C sells an object to B and B resells it to A and A directly pays the price to C in accordance with B's requests, the contract between A and B is canceled, should the money C received be considered unjust enrichment in relation to the A? Scholars of Korea and Germany have concurred with the view that the other party of the claim for refund is not C, but B. The reason is as follows: The reason A pays C is because A has a legal obligation to pay not to C, but B. The payment to C by A is the result of combining or shortening the payment process from A to B and from B to C. Therefore, if the contract between A and B is canceled, the restitution of unjust enrichment should take place between A and B. But the rulings of Supreme Court and the opinions of scholars did not concur in solving the similar problem in relation to the assignment between A and B. In case the contract between the obligor and the original obligee(assignor) is canceled after the credit of the latter is transferred and assignee of the credit is paid off, against whom does the obligor file a lawsuit for repayment? While the Supreme Court ruled that it is the assignee who should repay, I think that the original obligee(assignor) is under obligation to repay. The reasons are as follows: The obligor should not suffer a disadvantage in relation to the assignment. In case of unjust enrichment, originally the obligor bears the insolvency risk of the original obligee, the other party of the contract, but has no reason that he should bear the risk of the assignee. If the obligor cannot recover from the original obligee and should get back his payment from the assignee, he is unjustly subjected to a disadvantage in case that the assignee runs out of his funds.