Is Mercados G a scam, or is it legit?

My surname is Lu,operating a small-scale supermarket and living a prosperous life.At leisure,I like investing stock.In this August,I was pulled into a stock group,in which there were teachers who taught stock.Chatting with us, he taught us earning money by stock investment.He also gave me one-to-one analysis on stock.Having taught for some while,he said that the market was volatile and recommended us the CEHNTURAL platform.He asked us to deposit money into the platform to earn big money.Having seen that more and more person making profits,I deposited 1000000 yuan to trade followed by teacher without being resistant to the temptation.I did make profits on beginning days.On the day of end July, the teacher told us to add positions to make greater profits.I deposited another 200000 yuan,but only 100000 was left eventually.I felt something abnormal which I was reluctant to believe subconsciously.Additionally,whenever I made a loss,the salesman and order-recommendation teacher of the platform would talk nonsenses on terminology and urge me to add fund gain more profits than losses.I added fund to 400000 yuan in total.After making a loss of 200000 yuan,my remaining 90000 was in the status of closed position.I realized that I have been cheated and wanted to have a withdrawal.But the analyst asked me to add 100000 RMB for the withdrawal.