Fraudulent action of ngo

Hi,

We have deposited certain amount of money as EMD to a NGO for a certain work before 2 yrs. As Per agreement we had with them they were supposed to allot us work within 90 days or else they will return our money. But unfortunately neither they allotted any work nor money despite giving several written confirmation.  Now we want to file case against them.

Pls advice under which ipc we should file the case so that they should be punished exemplary.