Malicious guidance, loss of liquidation

The company is a black platform that delayed the transaction with severe slippage. They used the bonus as guise, which in fact is just a number and cannot be used at all. There is more than 600 yuan in the account, but the platform says it cannot be used. Please stay away! I contacted the platform after liquidation but received the reply three days later, saying that this is normal and that the bonus can't compensate the loss. But the platform neither said it in advance nor gave written notice. They are maliciously paralyzing customers.