Datawind — Aakash tablet (ubislate) delivery issue

I have pre-ordered UBISLATE (Aakash Tablet) on December 2011 (Booking ID: PME91F1) and I should get it on March 2012. On March I got a mail from Datawind to send the amount. I sent the amount Rs 2999/- Draft details:
DD No.-037809 (Union Bank of India) in favor of Datawind Innovations Pvt.Ltd. payable at Amritsar. I got a response back that I will get the Tablet in May with a sorry note saying "We regret for the inconvenience caused for delay." and till now I am getting Sorry notes and advance dates only.

Now a days.. I am not getting any response also on my queries, since June 2012, when I asked them I dont need the device, I need my money back.

Expecting help from you to get my device or money asap.
Appreciating your help.