Stock Market Loss

1)A client gave me his USER ID/PASSWORD & asked me to trade on his account. 2)The first week was good,made good profits. 3)After that one big loss blow the account away to 45k loss 4)I've stopped trading for him since then 5)He now wants money back.I've told him that losses are part of the game,but still he's not understanding it. 6)He's a normal man like everyone,i mean educated but still threatening me of going to SEBI/COURTS to make sure I'll suffer & maybe not do trading forever. 7)I've changed my mobile phone,so no chats are available on WhatsApp,even if he shows up somethings,everything is done like what I've mentioned in the opening statement. 8)Just for the losses he's threatening me of courts. Tell me lawyers,any steps to take to be safe ? Also i am broke now,since I've lost everything in stock markets. I've so far blocked me up every where & told him not to message me.