Datawind Aakash — Non-delivery of tablet and non refund of prepayment money even after 10 months of pre booking

I had booked an aaksah tablet (ubislate) with Datawind ( in Amritsar) in March 2012.. My booking Id is "PME92B3E3F2". I had made an advance payment of Rs.2999 by cheque at the time of booking. As per their claims on their website, the customers who make advance payments were to be delivered the tablet within 1 month. But till November they did not deliver. Each time I complained to them they said that they will definitely deliver the product within one month. In November 2012 I asked them to cancel my order and to refund my money. They sent me a mail asking for my bank account details. I replied to them accordingly. But its February 2013 and they have not refunded me my money. I have sent them dozens of mails requesting them for refund and for an update. But they are not responding to my mails as well.
So, its almost 1 year now and despite of making an advance payment I have neither received the tablet nor my money. Its nothing but fraud. And now, I just dont know how to get back my money.