Datawind Ubislate — Product not delivered even after 6 months of Payment

Address:

Bokaro, Jharkhand

Hello,
I am Joy Lal Chattaraj.
My father, (Jiban Lal Chattaraj) had ordered a tablet (Ucislate7c), made the payment in July, by cheque but they hadn't delivered the product.It was to be delivered in August, then September and still continuing.
On October 1 (after many e-mails send by me) the sent an offer to give an advanced version(7Ci) foe Rs.500 extra on delivery and they would deliver it within 72 hours, time passed by its end of December and i am still waiting. If i mail them the reply is:

Dear Sir,
We will contact you with delivery details.
Thanks

But they don't contact, neither they pickup phones.
The thing is I am Still waiting and I don't get an answer to how long shall I wait!
E mail ID: [protected]@gmail.com
[protected]@ [protected]
Please HELP!!
What Should I do??
Attachment: Confirmation of Payment by Datawind(e-mail snapshot) and Recent reply mail by datawind.