Won't let me withdraw my money 272k USD

I've in contact with this broker named Ms Lin and I have deposited 50k so I can do forex exchange. By the time I wanted to withdraw the money she won't let me do it and want me to pay additional tax on 272k. I refused to pay anything and my account has been frozen and now completely gone. Think you can help me with this case? I will provide all the information and the names that I have been in contact with.