my New iphone 14 pro max purchase on 27 sep and after activate showing date is April 1978. Why?

i bought iphone 14 pro max from Dubai and the phone was non activate, after purchase phone and login with my ID, the phone coverages showed expaired and date of purchase showing Aprill 1978. i have purchased 27 Sep 2023. Anyone plz tell how update my phone's currect purchase date and how srate my phon's covrage