Exa Technology — torturing to pay money

Sir/mam,
I am anjali from jharkhand. I am a student, i got a call saying that i had got a part time job so i have to fill 5000 captcha in 15 days and they asked me to send aadhar number, so i agreed to that.
But later i came to know that they have created a agreement saying that i have to pay 9000 as penalty if i don't complete work. I called them to ask about it but they didn't even respond to my call. But today they kept calling and harrassing me to pay 9000. I don't know what to do. I'm still a student and i'm poor. So please help me to get rid of them and i can't able to concentrate on...