Ubislate 7+ tab not received yet

Location/place: Orissa, Balangir

Name of company/service: Datawind Inovations Pvt Ltd

dr sir i booked ubislate 7+ tab in 02 Jan 2012 through there official site,,,,,and i paid in advance a DD for Rs 2999/-dated 25 Feb 2012,and they accept it as per their email.Sir now August is coming and at time of booking they told me that the delivery will be in March then April then May then June but still i empty handed and they are not responding the emails and as well as phone calls,,,,and from past three months they are telling one n only thing,, pl Waite for 10 to 15 days .
Now i want my money back now i am not interested in that product, i already send an email for refund but they are not responding pl help,,,,,,,