Pragnya IAS Institute - coaching insitute cheating faculty

I am working as facuty in an IAS institute. As per agreement with management of institute tey agreed to pay me Rs****/hr for economics classes. Totally I took ** hours of classes so the total comes to Rs ***** but they paid me only Rs***** (even this I got when I registered a complaint in the police station). When I am asking the person who recruited me he saying the Institute has been sold and management has been changed and they are saying that so many students opted out of the course when I took classes. The institute didn't said anything when I took classes, they are saying this when I am asking about my money. Pease help me out in this regard.