Cognizant Technology Solutions — Captcha project

I am sai i received a call regarding chaptcha work for 10000 chaptchs they didn't provided me software for 2 days then after i called them to provide software and to extend the 2days they didn't agreed for that and they are now asking me money of 6900 if not they will file a case against me i'm soo worried as i am a student i cannot pay that much amount pls help me i am worried