Sony India — Issue of Phone Warranty

Address:

New Delhi, Delhi

I purchased Sony Xperia C-2305 on 18th May, 2014 from The New Mobile Mart Shakarpur, Delhi-92, My Mobile screen was damaged on 16th Oct, 2014, My phone is under warranty So when i visited at Sony Service center for repair it, After checking they said my phone activated in Dec 2013, So its not in warranty. So i hereby attached my Bill Copy that i purchased it on 18th May 2014, So how could it possible that its activated in 22nd Dec, 2013, and not in warranty.