Dns Enterprise — form filling job

I was contacted by a person who works for dns enterprise. They told me that they are offering form filling jobs which pays 25rs per form. I have a target to complete 800 forms with 90% accuracy and if i fail to do so i will have to pay 4, 500 fine. They also provided a user id and password and told me to sign up at: https://formfillingworkspace.com/Account/Login
I agreed to a mou (Memorandum o[censored]nderstanding)
Back to the complaint, i was supposed to start work with them 21th june 2019, they tell me that if you don't done the complete work you will have to pay maintenance fees but when i completed the work they are asking me to pay the maintenance fees as i didn't complete the accuracy of 90% and they are also threatening me to take a legal action.
Please help me and tell me what should i do now.

When i searched through the internet i get to know that they have done this a lot time so can someone please tell me a way out of it.