Ibibo Group / Goibibo — Cash back not yet credited in credit card account

Website:

www.goibibo.com

I have booked a flight with an offer of getting Cashback of Rs. 1200 if I pay through HDFC credit card. It's been around 3 months now and the cashack has not been credited to my account which was meant to be credited within 45 days. Many times I have raised a ticket for the same but always the customer support ppl would say "please wait..It will take time". How much time Goibibo needs? Just tell clearly atleast if you are not going to give the Cashback. They are always telling me to wait, sometimes 3-4 days.. Sometimes 24-48 hrs but no result came out of this.
Is this what your offers are? Better I will stop booking from Goibibo and spread this as much as I can so that nobody else would suffer and trust on your offers which never gets fulfilled.