Refurbished by whom?
iPhone 6 and 6 plus may be one of the worst models to get refurbished:
In this case, they have been refurbished by a 3rd party manufacturer.
I got mine with a defective speaker (almost cant hear the caller) and broken satellite chip (so no navigation) with huge scratch marks on 2 sides.
So mind what you buy for 30% off.
The lack of navigation and broken speaker are issues you should contact customer service about, if you haven’t already. Scratch and Dent phones are supposed to only have cosmetic damages. Nothing that effects the functionality of the device.