They are using convincing tactics for scamming!

I got a call from someone in this company named Usama where he introduced himself and convinced me to deposit money. Then someone named Shadly started to call me. he said that if i deposit 1000$ he will give me 300$ as a bonus and we trade with this amount and if i loose the 300$ i will withdraw the money. Later on he told me to deposit 1500$ more so he can help me daily on trades but i only deposited 500$. We made profit our first trades. the amount was 2500$. I wanted to withdraw the whole amount and stop trading because i was risking a lot of money on trades with no stop loss. Shadly called me and told me to wait for the end of the month. he then opened several loosing trades in one hour and the amount became 750$ and if i haven't closed the trades manually it would have vanished. And so i stopped trading and it's been like 3 months and i'm writing mails to everyone in the company and no one is replying.