Forex Services — Threatening for not completing their task

I'm pradeep. From quikr i found this job as free registration and joined.
Later when i googled about the company many people said that it is fraud so i dropped from doing the job
After some days they sending me legal notices that i should pay them 8500 or they will file a case in gujarat session court.
Please help me i'm a ug student can't afford money.