Panasonic Smart Phone — about mobile

Address:

Gautam Buddh Nagar, Uttar Pradesh, 201305

I have purchased a 4g set of panasonic eluga a2, date _02/08/2017 but in mobile service care show the date_11/11/2016. How is possible. How can i manage warranty period. My phone give problem.
Shop address_ welcome mobile gallery,
Shop no. S-36, main bazar, chawla chowk, gandhidham-kutch.
Customer address - ashok kumar s/o rajendra prasad, vill-khorikhap, p. O - sihuli (Dargah) p. S - bandeya (Goh) dist.-aurangabad, state - bihar_824125
Mob. No._[protected]