I am using cash karo for past six months and have indeed received some small cash backs for the purchases done on several websites.
But unfortunately have never received cash backs for the big purchases done on snapdeal.com which were of about 33000 Rs.
I raised the issue with cash karo but every time they gave the reason that Snapdeal was not able trace the transaction at their end.
It seems like either Snapdeal or cash karo is not willing to pay the Cash back to the customers. The are just fooling us to buy online by showing these cash back offers.