Fraud platform. Do not recommend to deposit

I participated in one of their activities of refund the handling fee, and returned a total of a little more than 36 oil, and then I deposit another 100 to, and reached a total of 139 oil. I tried to withdraw 100, but they do not allow me to do so and said that I participated in the event and asked me to follow the rules of the event. I withdraw my principal, I don't withdraw what you return. They do not let me withdraw any of them.