Usually people complete Offers at the z8games Web page (For Crossfire NA Users).
In Crossfire Philippines I can not check because I do not Have an account, But I believe There would be Offers on their page as well.
Search around, if you find some simply complete and await your reward. I can not help you with the filling out process because I haven't done one from that website.
Good Luck. If You have further questions Post again or contact me.