SCAM BY VAST FOREX CANT WITHDRAW

Hello, I have top up funds to Vast Forex $7000-$8000 and when I have got some profits, I want to withdraw, but they asked me to pay tax first they transfer my funds, is it OK or it can be scamer? its almost 1 weeks all my money stuck in there. Can you help me to get my money back I think its scamers and they say my account will freeze if i dont pay the tax.