First thing you could do is stop providing any further money to your parents.
In my opinion, it will be rather difficult claiming your money back on account of several reasons. The most important one being that they are your parents and any money you gave shall be deemed part of a usual family transaction/ son's duty towards his family. Further, I doubt you have any proof of the amounts given or the fact that the same were meant to be 'loans'- to be returned to you by your father.
What you could perhaps do is lodge a complaint against the threats made to your life as well as the overall harassment caused. Do you have any evidence of the same? Those would, understandably, be necessary. You could also consider moving out to your own place.
A fact that might be questioned is from where you got so much money at the young age of 24. Hopefully you will have ready answers to that as well.
14th February 2013 From India , Delhi
19th April 2013 From India, Hyderabad