Please help me with the review of refurbished phones on ebay.

the seller has 100% rating and has been on ebay since 3 years.

This one is used, not refurbished more like it is Seller Refurbished
1. “This product comes with 6 Months Manufacturer or Brand warranty. Exact date of the warranty starts from the first buyer of the product and hence, the product might have more than 6 Months warranty or less than 6 Months warranty. In very rare cases, the warranty of the product might got expired and we request buyer to contact us in that case with service center letterhead stating that the product is “Out of Warranty”.

2. This product is returned by first buyer of the product to the manufacturer of maximum 3 to 4 days use and sold as an “Open Box” or “Unboxed” unit by the manufacturer to different retailer under Manufacturer Warranty.

And 1 and 2 points are contradicting each other, how come a 6month+ old phone be unboxed or seal opened?
These are most likely like new devices acquired from users online n offline
eBay.com is well known for refurbished phones, manufactures do sell new devices as refurbished there, here all are pre-owned. You may sometimes get a better phone, sometimes a bad phone