LS Decoration Co.'s workers paint the door of Sung's flat in mistaken belief that Sung's flat is the one they got an order to paint. In fact Chan is the neighbour. What would your legal advice be in the following circumstances: -

1. Sung had just been coming back from the office and watched without commenting while the workmen painted the door. He now refuses to pay when LS Decoration Co. send him a bill.
2. Sung discovers the door after the work is finished and is so delighted that he writes to LS Decoration Co. promising to pay for the work. Afterwards, he has second thoughts and does not want to pay.