Anna University — I'm complaining about caution deposit not refunded

I have passed out in 2015 from skr engineering college since from that there are cheating as by not give back the amount we paided at the time of joining.
There collected 5000 from each of as saying once we completed our degree our amount will be refunded back since many students asking them the amount there trying to threataing as.
So kindly take action about this compliant since i believe in law.
Thank you