Blackmailing to pay

I got a job in e zone enterprise company to fill 10000 captchas in ten days. The company executive signed agreement herself without informing and without my knowledge. After that i have received an id and password to fill captchas on mac2cap app. but I didn't complete this work due to network problem then the company told me that you have to pay penalty which is written in agreement that us 5000. An d i ready to pay it. But an executive of company told me that you have to pay 9500 to cancel agreement. And i ready to pay 9500 and also pay this amount in the company account. Then i have received a noc letter. After few days i have received a mail by e zone enterprise company's executive akhshay mistry he told me you have not pay amount to cancel agreement. You have to pay 14500 to cancel agreement. When i show my favour that i have already pay amount to cancel agreement then he told 9500 amount only for cancel work if you cancel agreement then you have to pay14500. Otherwise we will take legal notice and file a case against you. I am in trouble i have all proofs that prove this comapny only blackmailng me to earn more to more money please help me and give some suggestion to get rid of this problem