Not refunding money

&lt;p&gt;&lt;b&gt;Location/place&lt;/b&gt;: New Delhi&lt;/p&gt;<p><b>Name of company/service</b>: Datawind</p>I had booked a akash tab last year. They gave me a booking id. PM98DDB94CB. They gave me a offer to advance pay so i send a cheque of sum rs. 2999 bank-PNB which was debited on 24.03.12. They promised me to deliver the tab with in 10 days but not delivered it yet. So i wanted refund of my money now and i had mailed them about it but there is no reply from there side