Sahara Rajat Yojna — Money not being returned by Agent even after maturity

My mother had invested one lakh rupees in the Sahara Rajat Yojna scheme in 26-June-2003. Now after maturity, the agent is not giving back the money and instead he is saying that he has re-invested the money in another scheme which will mature in 2013.
The amount was invested in Bhagalpur branch in Bihar.
Now, we want our money back.
Please let us know whom to approach. Also now, we have left Bhagalpur (Bihar), and my mother stays in Delhi.