Bux-exchange

I was tricked by online scammers into paying around USD4,000 into this account for "futures trading". Of course, the initial trading looked like a 25% profit was being made. I became suspicious and tried to "Withdraw" at first 50% of my USDT to another platform...which was blocked. They have requested i deposit an additional 50% Security Fee to prove the withdrawal address is legitimate and has no violations of their regulations...of course this is all quite strange and if i did this would also be lost. Communications have now ceased with this company and my funds are locked in unable to retrieve.