After understanding the recent market financial environment and news, I decided to short the UK index product. Before trading, I consulted GMI's customer manager several times, and the reply was always that the UK index would not have dividends that day. So I placed an order to go short. But when I was ready to withdraw after making a profit, I saw a large amount of index dividend was deducted from my account. Isn't it obvious that the platform can’t accept client’s gain? Firstly, I consulted the customer manager of GMI platform in advance. The manager confirmed with his superior and back-office risk control for several times. The answer was always that 'there is no index dividend on the UK index this week’. Unlike other retail broker platforms, GMI platform doesn't actively send emails to inform customers of dividends, or publish data on the official website. I also asked proactively. Deducting the client’s index dividend afterwards is absolutely unreasonable; it is clearly the platform’s unilateral responsibility. After the event, I negotiated with the platform sales multiple times, but it was still ineffective.