Reliance Digital — Dell laptop purchased

I bought Dell Laptop on 19 Dec from Reliance Digital from Rajouri Garden Branch via Zest Money no cost EMI. I was being told to get a 10% cashback from Zest Money right after 3rd EMI. I had paid all EMIS but no cashback has been received till date. I am being writing to Zest Money since my 3rd EMI but such a painful experience to deal with them as there is a worst customer support on their end. This is making my experience bad with Reliance as well. Please refund my cashback asap.