Phuong was in serious financial difficulty. He approached his long-time friend Sylvia and asked to borrow $30,000 at very low interest. He promised to repay it at the end of one year. The year passed, and Sylvia asked him for the money. Phuong was still in financial difficulty. All he had was $20,000. Phuong told Sylvia that he could not repay it all and offered the $20,000. Phuong also knew that Sylvia had admired a painting that he owned. He asked her if she would take the painting to forgive him the balance of his debt. Sylvia agreed, and Phuong transferred $20,000 to Sylvia's account and had the painting delivered to her house. Sometime later Sylvia had the painting valued and it was officially estimated to be worth $125,000. When Phuong heard of this through a mutual friend, he rang Sylvia and told her that he is entitled to have the painting returned because its value far exceeded the original debt owed.

Using relevant cases discuss whether Phuong can force Sylvia to return the painting to him under the law of contract