Ebay.in — did not receive promotional gift

I am very disappointed with such a big branded website like ebay.in ....

in may-june of this year ebay had this special offer were if you buy worth 20000 you can use there coupon code and get a 64 gb pen drive.
i bought a sony xperia P which was more than 20000 and used the coupon code and was able to place the order.
i received the phone within a week and was happy but never got the pen drive.
i contacted there customer support and they said that pen drive would be sent once the offer was closed and would take 45 days.. so i waited..
but never got the pen drive.. i tried to contact them through there online chat and every time i was told that there is delay and should get it by next week..
it's December now over 7 months and still have not received and still when i call there customer support they say that there is a delay and i should
get in next week... one of the customer rep told me that he have escalated the case and i should get a call back which i never did. escalation complaint number is 1-[protected] after waiting for one week and to no shock to me i still did not got it so called again and this time the new rep from ebay told me the same thing that there has been a delay but its been shipped and gave me a tracking number for blue dart... and guess what??? that tracking number doesn't exist and when i call the blue dart they said that they have not recived any package from there end and this is a fake tracking number.... i think ebay is working to make some big scam ... i just want to know how i can drag them consumer court and also get this issue to better business bureau...

my phone number is [protected]
i am from faridabad , haryana