Frontech — harassing threatening me to give cancellation fee

Address:

760007

This company provided an agreement for form filling job on June 3rd and told to fill 1500 forms in 10 days within June 14. As per the agreement I had to get an accuracy of 90% with at least 1350 correct forms. I didn't get the accuracy and as per the agreement I paid them Rs.4500. Soon after that, I got a call from their legal department asking to pay Rs.25000 more. They threatened to file a case in the court under section 420 and if so I will have to pay Rs.45000 at the court so that the contract can be closed. No information regarding the cancellation of contact was specified in the agreement. Kindly help.
Contact no of the person who contacted me- [protected] and [protected]