Flex Enterprises — they are asking to pay extra 25500 amount apart from the .. agreement

Address:

Flex Enterprises, Kultan Wadi road, Aurangabad, Aurangabad, Maharashtra

I am srikailash, i had joined in flex on july 19 and as per the agreement i made mistakes and i paid the amount what i agreed in the agreement. On the date without any due.. And i got the noc but now they are asking to pay excess amount of 25500 within a day. They didn't mention about anything else in the agreement... They threatening and blackmail that they will spoil my studies.. Pls help me to come out from this problem