Csr( Captcha Service) Fraud/ Blackmail — company forced me to pay amount

I got a phn call on 16th july 2019 offering me a part time home based job of captache typing saying that if i complte 90% of correct captache within 10days i will earn 17500/- and in good faith i also agree to join... And on the same day an online agreement was done. Then i got a link to download their apps and after few days on 20th july i not able to login on my id i called them but didnt get any response i mailed me as try it now again i try to to login but it will not open... Then after 10days on 29th july there was a mail on my mail id saying me that she is preeti shinde calling from advocate associate and i have to pay the utility amount otherwise they will file a case against me..