Bought a "refurbished" iPhone 8 that Ebay seller claims has a new "100%" Battery/Battery Capacity, but I received a 83% Battery Capacity instead. Is seller lying?

Hi!

I recently bought a "refurbished" iPhone 8 that seller on Ebay claims has a new "100%" Battery/Battery Capacity, but I actually received a 83% Battery Capacity instead (as shown in the 'Battery Health & Charging" settings).

I submitted a request for a return and full refund because sellers description did not match the iPhone 8's actual condition. His response is questionable and I think he is lying. Can anyone verify what he is saying is true?

His response:

"All iPhone iOS are designed with over-charge protection so that one’s iPhone doesn’t become over-charged and damage the battery. Go into Settings > Battery > Battery Health & Charging and all, even new iPhones will show between 80-86% of Maximum Capacity, that is because of the Optimized Battery Charging setting. If you remove this setting by toggling it OFF. it will allow one to turn it off for a short period of time, but will revert itself back on, see “Turn Off Until Tomorrow” this setting is designed into the iPhone Operating System to prevent damaging and aging one’s battery. It says on the iPhone – To reduce battery aging, iPhone learns from your daily charging routine so it can wait to finish charging past 80% until you need to use it.

Proof that this battery image is the same phone, please note the in the fingerprint in the upper righthand corner, under the screen protector as in all other images. That image is throughout all of my images.

I suggest that you plug in the phone overnight to fully charge, this afternoon 03.08.2024 insert the T-Mobile SIM card into the phone and power it up. The phone should be unlocked and operational. If it’s not unlocked by close-of-business today I will refund you. AT&T will have sent me a confirmation e-mail on the status of the phone. The battery life issues is an iPhone iOS is a protective measure. "

I couple things he said are questionable. One that has me confused is that if it's indeed a new 100% battery wouldn't that obviously reflect 100% in the 'Battery Health & Charging'>'Maximum Capacity' settings regardless if it's an "iOS protective measure" as he says. And I quote,

"even new iPhones will show between 80-86% of Maximum Capacity, that is because of the Optimized Battery Charging setting."

Correct me if i'm misunderstanding what he is saying, but he is basically saying that the 'Maximum Capacity' appears to be of 83% only because an "iOS protective measure" and because the "Optimized Battery Charging" was turned ON, thus the battery capacity appears or is shown as 83%, but is still a new "100%"??? I turned this setting off as he told me, but it still says 83%. Is it true what he is saying. I think he's just lying. Can anyone verify if what he is saying is true?