PayTM - Used iPhone 7 sold as New

I ordered a "New" iPhone * from PayTM. When I received the phone, I attempted registering it online and found out that the warranty for that device is expired. I called apple care and they confirmed to me that the device warranty expires only if the phone has been used previously. This is a serious matter and that I need to speak with the seller to confirm whether the device sold to me is indeed a new phone or a pre-owned. I wrote back to PayTm. They refused to resolve the issue saying the images that I have sent to them are that of an old phone.