Timex — duplicate watch

Address:

Lucknow, Uttar Pradesh, 226016

I had buy timex tw002e114 analog watch from flipkart in may 2017. But after 6 month watch stop working and when we gone for repairing as it is under warranty. Service center is saying watch is duplicate we are not responsible, seller is not authorized. Who will responsible for this as we buyed from flipkart if seller is not authorized why flipkart sell this.
Invoice is attached