Iphone showing purchased in 1978

Hi there, if anyone is able to help me. I got gifted an iphone 14 pro max from the US as i am in the UK. The phone was purchased on 20/04 this year and the battery has already swollen. It was purchased from best buy, went to the apple store and they did their checks and it shows purchase date was 1978. Spoke to apple support team and even showed them proof but they said there's nothing they can do as it doesn't let them change it in the system and to go back to the third party (bestbuy) and tell them the situation and see if they can change it.

Any ideas if i was just being passed around by apple or if best buy can change the purchase date and would i have to send the phone back? Thank you :)