iPhone 8 Good as New battery complaint

I bought this phone, activated it on 26 Nov 2022. After a full charge the battery only lasted about 3 hours.

I went to 2 Vodacom stores in Menlyn Mall on 27 Nov 2022 and both gave me the same feedback: Many people come back with battery issues/complaints on the iPhone 8 refurbished phones.

The 7 days out of box failure is not applicable on these refurbished phones (which I think is totally wrong and *********). I have to send it for repairs and be without a phone for 1 to 2 weeks. However, I was told that most of the phones come back stating that the battery health is 100% and the battery is not replaced nor will it be replaced.

Although the battery health shows 100%, it seems like substandard or generic batteries are used and not genuine Apple iPhone batteries

I feel that this is totally unacceptable!

Who can this be escalated to please to have my phone or the battery replaced?