Black platform

The platform salesperson and account manager promised customers that in order to ensure the safety of customers' funds, they would allocate funds to customers. If they lose money, they would allocate funds to ensure the customer's funds. They promised that customers' funds could come and go freely and they could withdraw money at any time. However, the platform now refuses to provide funds. A customer withdraws money and says that the remaining money is allocation money. This is obviously a partnership fraud, and the money withdrawn by the customer cannot be directly transferred to the customer's account. What kind of behavior is this?