UbiSlate 7+ not received even after making advance payment in Feb’2012

Location/place: New Delhi

Name of company/service: DataWind Ltd.

I have complaint against DataWind Ltd., there website is ubislate.com

I have pre-booked The UbiSlate7+ is an Android 2.3 touch screen tablet on 16th Feb’2012 & sent the full advance cheque of Rs. 2999 through courier. (Scanned copy is attached herewith). My booking ID is: PM6A2A8402E5. The cheque has already been credited in their account. But 4 months have passed they have still not sent me the tablet. when I call them to their cutomer care numbers they rarely pick the phone. The always give me new date of delivery. Please help me.