Wieon Enterprise — they are calling me to pay penalty amount

I was given a workload of 150 pages to do within 15 days. If didn't achieved accuracy they need 10000 rupees as penalty.
With lot of hard work i done the project and submitted but they are saying that the project is of no accuracy.
When i checked the agreement it was stamped twice with another date.
They are a fraud company.
Anyway they are not going to pay me even if i achieved 100% accuracy in my work.
I kindly request to help me get rid out of this situation.
They are keeping on calling and messaging for the money