Exa Technology — fake agreement harassment

Hello sir, i'm gopinath biswal from odisha and i'm a student, i got a call saying that i had got a part time job so i have to fill 15000 captcha in 15 days and they asked me to send voter id, so i agreed to that. I checked aggrement that is fake so i said him for not doing work at 1st day
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 my exam.