Consumer Redressal

I bought a "HTC Desire 816" costing around Rs. 24000 from Reliance Digital store at Axis Mall in the month of September 2014. Out of the two sim slots, one was defective (one pin broken) from beginning. Since the second sim slot worked, we also did not realize this. After around one and half month, the second sim slot also stopped working. So we went back to the store, they said it might be a sim issue and suggested to go to Airtel shop or HTC service center. We went to Airtel and they confirmed that it's not a sim issue. Then we went to HTC service center where they pointed out that since the first sim slot was defective it could be covered in warranty as there's a physical damage. As this set has the sim slots attached with the mother board, the whole board will have to change which will cost around 10000. They suggested to go back to the reliance store and talk to them. Then we went back only to hear from Reliance store that "you should have come back within 7 days". Please help.