Longasiaand the agent traded on behalf of the client, sending me a related transaction contract

Longasia and the agent traded on behalf of the customer. They sent me a related transaction contract. However, orders were made by them in opposite way, and they didn’t let me trade, keeping me losing money. I complained to the customer service personnel, but they shirk responsibility, saying that the agent has nothing to do with them. Is that reasonable? Hope to solve the problem.