My device is 3 months old and it battery drain 100 at 3 hours and 30 minutes whatt is this rubbish

I had purchased this smartphone samsung galaxy a35 at brand new condition but it's battery backup is too much poor it gives approx 3 hours or battery backup what rubbish samsung

Hello SamsungI have recently purchased a new SAMSUNG GALAXY A35 5G and when I try to connect with 5G network it connects and it will automatically switch to 4G. make sure any upcoming update about stable 5g many users not buying this phone for 5gTh...